JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Activation of HIV Transcription with Short-Course Vorinostat in HIV-Infected Patients on Suppressive Antiretroviral Therapy.
PLoS Pathog.
PUBLISHED: 11-01-2014
Show Abstract
Hide Abstract
Human immunodeficiency virus (HIV) persistence in latently infected resting memory CD4+ T-cells is the major barrier to HIV cure. Cellular histone deacetylases (HDACs) are important in maintaining HIV latency and histone deacetylase inhibitors (HDACi) may reverse latency by activating HIV transcription from latently infected CD4+ T-cells. We performed a single arm, open label, proof-of-concept study in which vorinostat, a pan-HDACi, was administered 400 mg orally once daily for 14 days to 20 HIV-infected individuals on suppressive antiretroviral therapy (ART). The primary endpoint was change in cell associated unspliced (CA-US) HIV RNA in total CD4+ T-cells from blood at day 14. The study is registered at ClinicalTrials.gov (NCT01365065). Vorinostat was safe and well tolerated and there were no dose modifications or study drug discontinuations. CA-US HIV RNA in blood increased significantly in 18/20 patients (90%) with a median fold change from baseline to peak value of 7.4 (IQR 3.4, 9.1). CA-US RNA was significantly elevated 8 hours post drug and remained elevated 70 days after last dose. Significant early changes in expression of genes associated with chromatin remodeling and activation of HIV transcription correlated with the magnitude of increased CA-US HIV RNA. There were no statistically significant changes in plasma HIV RNA, concentration of HIV DNA, integrated DNA, inducible virus in CD4+ T-cells or markers of T-cell activation. Vorinostat induced a significant and sustained increase in HIV transcription from latency in the majority of HIV-infected patients. However, additional interventions will be needed to efficiently induce virus production and ultimately eliminate latently infected cells.
Related JoVE Video
Comparison of Etests and Vitek 2(®) to broth microdilution for the susceptibility testing of Cryptococcus neoformans.
Diagn. Microbiol. Infect. Dis.
PUBLISHED: 06-09-2014
Show Abstract
Hide Abstract
We determined the susceptibility of 102 clinical isolates Cryptococcus neoformans from Durban, South Africa, to amphotericin B, fluconazole, flucytosine, and voriconazole using broth microdilution (BMD) according to the Clinical and Laboratory Standards Institute M27-A3 document and compared these results with Etest and Vitek 2(®). Essential agreement (EA) of Etest and Vitek 2(®) compared to BMD was determined. Low MICs that were below the epidemiological cutoff values of the 4 antifungal agents tested were demonstrated by all isolates. The EA of Etests for fluconazole, amphotericin, and voriconazole was 95.1%, 83.3%, and 91.2%, respectively, and for Vitek 2(®) EA for fluconazole, amphotericin, and flucytosine was 97.1%, 95.1%, and 97.1%, respectively. The Vitek 2(®) showed good agreement with BMD and is a suitable alternative. Etests demonstrated good EA for azoles only. Clinical cryptococcal isolates from Durban remain susceptible to current recommended antifungal therapy.
Related JoVE Video
HIV infection: epidemiology, pathogenesis, treatment, and prevention.
Lancet
PUBLISHED: 06-05-2014
Show Abstract
Hide Abstract
HIV prevalence is increasing worldwide because people on antiretroviral therapy are living longer, although new infections decreased from 3.3 million in 2002, to 2.3 million in 2012. Global AIDS-related deaths peaked at 2.3 million in 2005, and decreased to 1.6 million by 2012. An estimated 9.7 million people in low-income and middle-income countries had started antiretroviral therapy by 2012. New insights into the mechanisms of latent infection and the importance of reservoirs of infection might eventually lead to a cure. The role of immune activation in the pathogenesis of non-AIDS clinical events (major causes of morbidity and mortality in people on antiretroviral therapy) is receiving increased recognition. Breakthroughs in the prevention of HIV important to public health include male medical circumcision, antiretrovirals to prevent mother-to-child transmission, antiretroviral therapy in people with HIV to prevent transmission, and antiretrovirals for pre-exposure prophylaxis. Research into other prevention interventions, notably vaccines and vaginal microbicides, is in progress.
Related JoVE Video
Lipopolysaccharide, immune activation, and liver abnormalities in HIV/hepatitis B virus (HBV)-coinfected individuals receiving HBV-active combination antiretroviral therapy.
J. Infect. Dis.
PUBLISHED: 02-28-2014
Show Abstract
Hide Abstract
We investigated the relationship between microbial translocation, immune activation, and liver disease in human immunodeficiency virus (HIV)/hepatitis B virus (HBV) coinfection. Lipopolysaccharide (LPS), soluble CD14, CXCL10, and CCL-2 levels were elevated in patients with HIV/HBV coinfection. Levels of LPS, soluble CD14, and CCL-2 declined following receipt of HBV-active combination antiretroviral therapy (cART), but the CXCL10 level remained elevated. No markers were associated with liver disease severity on liver biopsy (n = 96), but CXCL10, interleukin 6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor ?, and interferon ? (IFN-?) were all associated with elevated liver enzyme levels during receipt of HBV-active cART. Stimulation of hepatocyte cell lines in vitro with IFN-? and LPS induced a profound synergistic increase in the production of CXCL10. LPS may contribute to liver disease via stimulating persistent production of CXCL10.
Related JoVE Video
Compartmentalization of innate immune responses in the central nervous system during cryptococcal meningitis/HIV coinfection.
AIDS
PUBLISHED: 01-24-2014
Show Abstract
Hide Abstract
The role of innate immunity in the pathogenesis of cryptococcal meningitis is unclear. We hypothesized that natural killer (NK) cell and monocyte responses show central nervous system (CNS) compartment-specific profiles, and are altered by antifungal therapy and combination antiretroviral therapy (cART) during cryptococcal meningitis/HIV coinfection.
Related JoVE Video
CXCL-10, interleukin-12 and interleukin-21 are not immunological predictors of HBeAg seroconversion in HIV-1-HBV coinfection following HBV-active antiretroviral therapy.
Antivir. Ther. (Lond.)
PUBLISHED: 01-16-2014
Show Abstract
Hide Abstract
Interferon stimulated chemokine CXCL-10, interleukin (IL)-12 (p70) and IL-21 have been associated with HBsAg and HBeAg loss following treatment of HBV monoinfection. The aim of this study was to determine whether these factors were also associated with HBsAg and HBeAg loss in HIV-HBV-coinfected patients following HBV-active combination antiretroviral therapy (cART).
Related JoVE Video
Hepatitis C prevalence among HIV-infected patients in Guinea-Bissau: a descriptive cross-sectional study.
Int. J. Infect. Dis.
PUBLISHED: 01-02-2014
Show Abstract
Hide Abstract
To estimate the prevalence and determine the clinical presentation of risk factors of hepatitis C virus (HCV) among HIV-infected patients in Bissau, Guinea-Bissau.
Related JoVE Video
Ex Vivo Response to Histone Deacetylase (HDAC) Inhibitors of the HIV Long Terminal Repeat (LTR) Derived from HIV-Infected Patients on Antiretroviral Therapy.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Histone deacetylase inhibitors (HDACi) can induce human immunodeficiency virus (HIV) transcription from the HIV long terminal repeat (LTR). However, ex vivo and in vivo responses to HDACi are variable and the activity of HDACi in cells other than T-cells have not been well characterised. Here, we developed a novel assay to determine the activity of HDACi on patient-derived HIV LTRs in different cell types. HIV LTRs from integrated virus were amplified using triple-nested Alu-PCR from total memory CD4+ T-cells (CD45RO+) isolated from HIV-infected patients prior to and following suppressive antiretroviral therapy. NL4-3 or patient-derived HIV LTRs were cloned into the chromatin forming episomal vector pCEP4, and the effect of HDACi investigated in the astrocyte and epithelial cell lines SVG and HeLa, respectively. There were no significant differences in the sequence of the HIV LTRs isolated from CD4+ T-cells prior to and after 18 months of combination antiretroviral therapy (cART). We found that in both cell lines, the HDACi panobinostat, trichostatin A, vorinostat and entinostat activated patient-derived HIV LTRs to similar levels seen with NL4-3 and all patient derived isolates had similar sensitivity to maximum HDACi stimulation. We observed a marked difference in the maximum fold induction of luciferase by HDACi in HeLa and SVG, suggesting that the effect of HDACi may be influenced by the cellular environment. Finally, we observed significant synergy in activation of the LTR with vorinostat and the viral protein Tat. Together, our results suggest that the LTR sequence of integrated virus is not a major determinant of a functional response to an HDACi.
Related JoVE Video
No Difference in the Rate of Change in Telomere Length or Telomerase Activity in HIV-Infected Patients after Three Years of Darunavir/Ritonavir with and without Nucleoside Analogues in the MONET Trial.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
To determine whether nucleos(t)ide reverse transcriptase inhibitors (NRTI) contribute to an accelerated loss in telomere length (TL) in HIV-infected patients on antiretroviral therapy (ART).
Related JoVE Video
Hepatitis B and Delta virus are prevalent but often subclinical co-infections among HIV infected patients in Guinea-Bissau, West Africa: a cross-sectional study.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Co-infection with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) may lead to accelerated hepatic disease progression with higher rates of liver cirrhosis and liver-related mortality compared with HBV mono-infection. Co or super-infection with hepatitis Delta virus (HDV) may worsen the liver disease and complicate treatment possibilities.
Related JoVE Video
An In-Depth Comparison of Latent HIV-1 Reactivation in Multiple Cell Model Systems and Resting CD4+ T Cells from Aviremic Patients.
PLoS Pathog.
PUBLISHED: 12-01-2013
Show Abstract
Hide Abstract
The possibility of HIV-1 eradication has been limited by the existence of latently infected cellular reservoirs. Studies to examine control of HIV latency and potential reactivation have been hindered by the small numbers of latently infected cells found in vivo. Major conceptual leaps have been facilitated by the use of latently infected T cell lines and primary cells. However, notable differences exist among cell model systems. Furthermore, screening efforts in specific cell models have identified drug candidates for "anti-latency" therapy, which often fail to reactivate HIV uniformly across different models. Therefore, the activity of a given drug candidate, demonstrated in a particular cellular model, cannot reliably predict its activity in other cell model systems or in infected patient cells, tested ex vivo. This situation represents a critical knowledge gap that adversely affects our ability to identify promising treatment compounds and hinders the advancement of drug testing into relevant animal models and clinical trials. To begin to understand the biological characteristics that are inherent to each HIV-1 latency model, we compared the response properties of five primary T cell models, four J-Lat cell models and those obtained with a viral outgrowth assay using patient-derived infected cells. A panel of thirteen stimuli that are known to reactivate HIV by defined mechanisms of action was selected and tested in parallel in all models. Our results indicate that no single in vitro cell model alone is able to capture accurately the ex vivo response characteristics of latently infected T cells from patients. Most cell models demonstrated that sensitivity to HIV reactivation was skewed toward or against specific drug classes. Protein kinase C agonists and PHA reactivated latent HIV uniformly across models, although drugs in most other classes did not.
Related JoVE Video
Myeloid Dendritic Cells Induce HIV-1 Latency in Non-proliferating CD4(+) T Cells.
PLoS Pathog.
PUBLISHED: 12-01-2013
Show Abstract
Hide Abstract
Latently infected resting CD4(+) T cells are a major barrier to HIV cure. Understanding how latency is established, maintained and reversed is critical to identifying novel strategies to eliminate latently infected cells. We demonstrate here that co-culture of resting CD4(+) T cells and syngeneic myeloid dendritic cells (mDC) can dramatically increase the frequency of HIV DNA integration and latent HIV infection in non-proliferating memory, but not naïve, CD4(+) T cells. Latency was eliminated when cell-to-cell contact was prevented in the mDC-T cell co-cultures and reduced when clustering was minimised in the mDC-T cell co-cultures. Supernatants from infected mDC-T cell co-cultures did not facilitate the establishment of latency, consistent with cell-cell contact and not a soluble factor being critical for mediating latent infection of resting CD4(+) T cells. Gene expression in non-proliferating CD4(+) T cells, enriched for latent infection, showed significant changes in the expression of genes involved in cellular activation and interferon regulated pathways, including the down-regulation of genes controlling both NF-?B and cell cycle. We conclude that mDC play a key role in the establishment of HIV latency in resting memory CD4(+) T cells, which is predominantly mediated through signalling during DC-T cell contact.
Related JoVE Video
Entinostat is a histone deacetylase inhibitor selective for class 1 histone deacetylases and activates HIV production from latently infected primary T cells.
AIDS
PUBLISHED: 11-06-2013
Show Abstract
Hide Abstract
To compare the potency, toxicity and mechanism of action of multiple histone deacetylase inhibitors (HDACi) in activating HIV production from latency.
Related JoVE Video
HIV-1 envelope-receptor interactions required for macrophage infection and implications for current HIV-1 cure strategies.
J. Leukoc. Biol.
PUBLISHED: 10-24-2013
Show Abstract
Hide Abstract
Myeloid cells residing in the CNS and lymphoid tissues are targets for productive HIV-1 replication, and their infection contributes to the pathological manifestations of HIV-1 infection. The Envs can adopt altered configurations to overcome entry restrictions in macrophages via a more efficient and/or altered mechanism of engagement with cellular receptors. This review highlights evidence supporting an important role for macrophages in HIV-1 pathogenesis and persistence, which need to be considered for strategies aimed at achieving a functional or sterilizing cure. We also highlight that the molecular mechanisms underlying HIV-1 tropism for macrophages are complex, involving enhanced and/or altered interactions with CD4, CCR5, and/or CXCR4, and that the nature of these interactions may depend on the anatomical location of the virus.
Related JoVE Video
The end of AIDS: HIV infection as a chronic disease.
Lancet
PUBLISHED: 10-23-2013
Show Abstract
Hide Abstract
The success of antiretroviral therapy has led some people to now ask whether the end of AIDS is possible. For patients who are motivated to take therapy and who have access to lifelong treatment, AIDS-related illnesses are no longer the primary threat, but a new set of HIV-associated complications have emerged, resulting in a novel chronic disease that for many will span several decades of life. Treatment does not fully restore immune health; as a result, several inflammation-associated or immunodeficiency complications such as cardiovascular disease and cancer are increasing in importance. Cumulative toxic effects from exposure to antiretroviral drugs for decades can cause clinically-relevant metabolic disturbances and end-organ damage. Concerns are growing that the multimorbidity associated with HIV disease could affect healthy ageing and overwhelm some health-care systems, particularly those in resource-limited regions that have yet to develop a chronic care model fully. In view of the problems inherent in the treatment and care for patients with a chronic disease that might persist for several decades, a global effort to identify a cure is now underway.
Related JoVE Video
Targets for intervention to improve virological outcomes for patients receiving free antiretroviral therapy in Tamil Nadu, India.
AIDS Care
PUBLISHED: 10-15-2013
Show Abstract
Hide Abstract
Operational research to identify factors predicting poor clinical outcomes is critical to maximize patient care and prolong first-line regimens for those receiving free antiretroviral therapy (ART) in India. We sought to identify social or clinical factors amenable to intervention that predict virological outcomes after 12 months of ART. We examined a retrospective cohort of consecutive adults initiating free nonnucleoside reverse transcriptase inhibitor-based regimens. Individuals remaining in care 12 months post-ART initiation were tested for HIV viral load and surveyed to identify barriers and facilitators to adherence, and to determine clinic travel times and associated costs. Uni- and multivariate logistic regression identified factors predicting HIV viral load >200 copies/mL after 12 months of ART. Of 230 adults initiating ART, 10% of patients died, 8% transferred out, 5% were lost to follow-up, and 174/230 (76%) completed 12 months of ART, the questionnaire, and viral load testing. HIV viral load was <200 copies/mL in 140/174 (80%) patients. In multivariate models, being busy with work or caring for others (OR 2.9, p < 0.01), having clinic transport times ? 3 hours (OR 3.0, p = 0.02), and alcohol use (OR 4.8, p = 0.03) predicted viral load >200 copies/mL after 12 months of ART. Clinical outcomes following ART are related to programmatic factors such as prolonged travel time and individual factors such as being busy with family or using alcohol. Simple interventions that alter these factors should be evaluated to improve clinical outcomes for populations receiving free ART in similar settings.
Related JoVE Video
Chemokine levels and chemokine receptor expression in the blood and the cerebrospinal fluid of HIV-infected patients with cryptococcal meningitis and cryptococcosis-associated immune reconstitution inflammatory syndrome.
J. Infect. Dis.
PUBLISHED: 08-01-2013
Show Abstract
Hide Abstract
Human immunodeficiency virus-infected patients with treated cryptococcal meningitis who start combination antiretroviral therapy (cART) are at risk of further neurological deterioration, in part caused by paradoxical cryptococcosis-associated immune reconstitution inflammatory syndrome (C-IRIS). We hypothesized that C-IRIS is associated with alterations of chemokine receptor expression on T cells and chemokine concentrations in cerebrospinal fluid (CSF) that enhance recruitment of T-helper 1 cells and/or myeloid cells to the central nervous system.
Related JoVE Video
Related JoVE Video
HIV and co-infections.
Immunol. Rev.
PUBLISHED: 06-19-2013
Show Abstract
Hide Abstract
Despite significant reductions in morbidity and mortality secondary to availability of effective combination anti-retroviral therapy (cART), human immunodeficiency virus (HIV) infection still accounts for 1.5 million deaths annually. The majority of deaths occur in sub-Saharan Africa where rates of opportunistic co-infections are disproportionately high. In this review, we discuss the immunopathogenesis of five common infections that cause significant morbidity in HIV-infected patients globally. These include co-infection with Mycobacterium tuberculosis, Cryptococcus neoformans, hepatitis B virus, hepatitis C virus, and Plasmodium falciparum. Specifically, we review the natural history of each co-infection in the setting of HIV, the specific immune defects induced by HIV, the effects of cART on the immune response to the co-infection, the pathogenesis of immune restoration disease (IRD) associated with each infection, and advances in the areas of prevention of each co-infection via vaccination. Finally, we discuss the opportunities and gaps in knowledge for future research.
Related JoVE Video
Cryptococcosis-IRIS is associated with lower cryptococcus-specific IFN-? responses before antiretroviral therapy but not higher T-cell responses during therapy.
J. Infect. Dis.
PUBLISHED: 06-12-2013
Show Abstract
Hide Abstract
Cryptococcosis-associated immune reconstitution inflammatory syndrome (C-IRIS) may be driven by aberrant T-cell responses against cryptococci. We investigated this in human immunodeficiency virus (HIV)-infected patients with treated cryptococcal meningitis (CM) commencing combination antiretroviral therapy (cART).
Related JoVE Video
Associations between surface markers on blood monocytes and carotid atherosclerosis in HIV-positive individuals.
Immunol. Cell Biol.
PUBLISHED: 05-26-2013
Show Abstract
Hide Abstract
Chronic HIV infection is associated with increased risk of cardiovascular disease (CVD), including in patients with virological suppression. Persistent innate immune activation may contribute to the development of CVD via activation of monocytes in these patients. We investigated whether changes in monocyte phenotype predict subclinical atherosclerosis in virologically suppressed HIV-positive individuals with low cardiovascular risk. We enroled 51 virologically suppressed HIV-positive individuals not receiving protease inhibitors or statins and 49 age-matched uninfected controls in this study. Carotid artery intima-media thickness (cIMT) was used as a surrogate marker for CVD, and traditional risk factors, including Framingham risk scores, were recorded. Markers of monocyte activation (CD14, CD16, CCR2, CX3CR1, CD38, HLA-DR and CD11b) were measured in whole-blood samples by flow cytometry. Associations were assessed using univariate and multivariate median regressions. Median cIMT was similar between HIV-positive and HIV-negative participants (P=0.3), although HIV-positive patients had significantly higher Framingham risk score (P=0.009) and systemic inflammation. Expression of two monocyte markers, CD11b and CX3CR1, independently predicted carotid artery thickness in HIV-positive individuals after controlling for Framingham risk score (P=0.025 and 0.015, respectively). These markers were not predictive of carotid artery thickening in controls. Our study indicates that monocyte surface markers may serve as novel predictors of CVD in HIV-positive individuals and is consistent with an important role for monocyte activation in the progression of HIV-related cardiovascular pathology.Immunology and Cell Biology advance online publication, 3 December 2013; doi:10.1038/icb.2013.84.
Related JoVE Video
A common mechanism of clinical HIV-1 resistance to the CCR5 antagonist maraviroc despite divergent resistance levels and lack of common gp120 resistance mutations.
Retrovirology
PUBLISHED: 04-17-2013
Show Abstract
Hide Abstract
The CCR5 antagonist maraviroc (MVC) inhibits human immunodeficiency virus type 1 (HIV-1) entry by altering the CCR5 extracellular loops (ECL), such that the gp120 envelope glycoproteins (Env) no longer recognize CCR5. The mechanisms of HIV-1 resistance to MVC, the only CCR5 antagonist licensed for clinical use are poorly understood, with insights into MVC resistance almost exclusively limited to knowledge obtained from in vitro studies or from studies of resistance to other CCR5 antagonists. To more precisely understand mechanisms of resistance to MVC in vivo, we characterized Envs isolated from 2 subjects who experienced virologic failure on MVC.
Related JoVE Video
Clinical and mycological predictors of cryptococcosis-associated Immune reconstitution inflammatory syndrome (C-IRIS).
AIDS
PUBLISHED: 03-26-2013
Show Abstract
Hide Abstract
OBJECTIVE:: HIV-infected patients with treated cryptococcal meningitis (CM) are at risk of further neurological deterioration (ND) after commencing combination antiretroviral therapy (cART), mostly due to cryptococcosis-associated immune reconstitution inflammatory syndrome (C-IRIS). Identifying predictors of C-IRIS could enable risk stratification strategies. DESIGN:: Prospective, longitudinal cohort study for 24 weeks. SETTING:: Durban, South Africa. SUBJECTS:: 130 HIV-infected patients experiencing first episode of CM. INTERVENTION:: Antifungal therapy (Amphotericin 1?mg/kg median 14 days, followed by consolidation and maintenance fluconazole) and cART (commenced median of 18 days from CM diagnosis). MAIN OUTCOME MEASURE:: Rate of C-IRIS and clinical, blood and CSF markers associated with C-IRIS before and during ART. Clinical significance of CSF cryptococcal culture negativity pre-cART commencement. RESULTS:: Of 106 patients commencing cART, 27 (25.5%) developed C-IRIS, 16 (15.1%) ND-not C-IRIS and 63 (59.4%) no-ND. On multivariable analysis, lower CD4+ T-cell increases on cART (Hazard ratio HR 0.99, p?=?0.026), persistent CSF cryptococcal growth (HR 0.27, p?=?0.026) and lower CSF protein (HR 0.53, p?=?0.059) prior to cART initiation were associated with C-IRIS. Using survival analysis, patients with a negative cryptococcal culture pre-cART commencement (n?=?51; 48.1%) experienced fewer episodes of ND, C-IRIS and cryptococcal relapse/persistence than patients with a positive CSF culture (n?=?55; 51.9%, HR 0.33, 0.33 and 0.12 and p?=?0.0003, 0.0042 and, 0.0004, respectively). CONCLUSIONS:: Persistent CSF cryptococcal growth at cART initiation and poor CD4+ T-cell increases on cART are strong predictors of C-IRIS. Approaches aimed at achieving CSF culture negativity prior to cART should be evaluated as a strategy to reduce rates of C-IRIS.
Related JoVE Video
The search for an HIV cure: tackling latent infection.
Lancet Infect Dis
PUBLISHED: 03-05-2013
Show Abstract
Hide Abstract
Strategies to eliminate infectious HIV that persists despite present treatments and with the potential to cure HIV infection are of great interest. One patient seems to have been cured of HIV infection after receiving a bone marrow transplant with cells resistant to the virus, although this strategy is not viable for large numbers of infected people. Several clinical trials are underway in which drugs are being used to activate cells that harbour latent HIV. In a recent study, investigators showed that activation of latent HIV infection in patients on antiretroviral therapy could be achieved with a single dose of vorinostat, a licensed anticancer drug that inhibits histone deacetylase. Although far from a cure, such studies provide some guidance towards the logical next steps for research. Clinical studies that use a longer duration of drug dosing, alternative agents, combination approaches, gene therapy, and immune-modulation approaches are all underway.
Related JoVE Video
Pharmacy and self-report adherence measures to predict virological outcomes for patients on free antiretroviral therapy in Tamil Nadu, India.
AIDS Behav
PUBLISHED: 02-26-2013
Show Abstract
Hide Abstract
Over 480,000 individuals receive free antiretroviral therapy (ART) in India yet data associating ART adherence with HIV viral load for populations exclusively receiving free ART are not available. Additionally estimates of adherence using pharmacy data on ART pick-up are not available for any population in India. After 12-months ART we found self-reported estimates of adherence were not associated with HIV viral load. Individuals with <100% adherence using pharmacy data predicted HIV viral load, and estimates combining pharmacy data and self-report were also predictive. Pharmacy adherence measures proved a feasible method to estimate adherence in India and appear more predictive of virological outcomes than self-report. Predictive adherence measures identified in this study warrant further investigation in populations receiving free ART in India to allow for identification of individuals at risk of virological failure and in need of adherence support.
Related JoVE Video
The magnitude of HIV-1 resistance to the CCR5 antagonist maraviroc may impart a differential alteration in HIV-1 tropism for macrophages and T-cell subsets.
Virology
PUBLISHED: 01-31-2013
Show Abstract
Hide Abstract
Human immunodeficiency virus type 1 (HIV-1) resistance to CCR5 antagonists, including maraviroc (MVC), results from alterations in the HIV-1 envelope glycoproteins (Env) enabling recognition of antagonist-bound CCR5. Here, we characterized tropism alterations for CD4+ T-cell subsets and macrophages by Envs from two subjects who developed MVC resistance in vivo, which displayed either relatively efficient or inefficient recognition of MVC-bound CCR5. We show that MVC-resistant Env with efficient recognition of drug-bound CCR5 displays a tropism shift for CD4+ T-cell subsets associated with increased infection of central memory T-cells and reduced infection of effector memory and transitional memory T-cells, and no change in macrophage infectivity. In contrast, MVC-resistant Env with inefficient recognition of drug-bound CCR5 displays no change in tropism for CD4+ T-cell subsets, but exhibits a significant reduction in macrophage infectivity. The pattern of HIV-1 tropism alterations for susceptible cells may therefore be variable in subjects with MVC resistance.
Related JoVE Video
Comparison of HDAC inhibitors in clinical development: effect on HIV production in latently infected cells and T-cell activation.
Hum Vaccin Immunother
PUBLISHED: 01-31-2013
Show Abstract
Hide Abstract
We aimed to compare the potential for inducing HIV production and the effect on T-cell activation of potent HDAC inhibitors undergoing clinical investigation.
Related JoVE Video
Biomarkers of inflammation and coagulation are associated with mortality and hepatitis flares in persons coinfected with HIV and hepatitis viruses.
J. Infect. Dis.
PUBLISHED: 01-18-2013
Show Abstract
Hide Abstract
Hepatitis C virus (HCV) and/or hepatitis B virus (HBV) coinfection with human immunodeficiency virus (HIV) has a greater risk of mortality than either HCV or HBV infection alone and is frequently associated with hepatitis flares after antiretroviral therapy (ART) initiation.
Related JoVE Video
Patterns and causes of suboptimal response to tenofovir-based therapy in individuals coinfected with HIV and hepatitis B virus.
Clin. Infect. Dis.
PUBLISHED: 01-11-2013
Show Abstract
Hide Abstract
Tenofovir (TDF) is effective for treatment of hepatitis B virus (HBV) in human immunodeficiency virus (HIV) infection; however, some individuals have ongoing HBV viremia, the reasons for which are unclear. We determined the patterns and factors associated with detectable HBV DNA in HIV-HBV-coinfected subjects on highly active antiretroviral therapy (HAART).
Related JoVE Video
Inhibition of telomerase activity by human immunodeficiency virus (HIV) nucleos(t)ide reverse transcriptase inhibitors: a potential factor contributing to HIV-associated accelerated aging.
J. Infect. Dis.
PUBLISHED: 01-09-2013
Show Abstract
Hide Abstract
Human immunodeficiency virus (HIV)-infected patients on combination active antiretroviral therapy (cART) are at increased risk of age-related complications. We hypothesized that nucleos(t)ide reverse transcriptase inhibitors (NRTI) may contribute to accelerated aging in HIV-infected individuals on cART via inhibition of telomerase activity.
Related JoVE Video
Is specific HIV eradication from the brain possible or needed?
Expert Opin Biol Ther
PUBLISHED: 01-05-2013
Show Abstract
Hide Abstract
There is increasing interest in the possibility of eradication of HIV, given the recent case reports. However, it is not clear to what extent brain involvement by HIV poses a challenge to systemic eradication strategies.
Related JoVE Video
Targeting antigen to bone marrow stromal cell-2 expressed by conventional and plasmacytoid dendritic cells elicits efficient antigen presentation.
Eur. J. Immunol.
PUBLISHED: 01-04-2013
Show Abstract
Hide Abstract
Bone marrow stromal cell-2 (BST-2) has major roles in viral tethering and modulation of interferon production. Here we investigate BST-2 as a receptor for the delivery of antigen to dendritic cells (DCs). We show that BST-2 is expressed by a panel of mouse and human DC subsets, particularly under inflammatory conditions. The outcome of delivering antigen to BST-2 expressed by steady state and activated plasmacytoid DC (pDC) or conventional CD8(+) and CD8(-) DCs was determined. T-cell responses were measured for both MHC class I (MHCI) and MHC class II (MHCII) antigen presentation pathways in vitro. Delivering antigen via BST-2 was compared with that via receptors DEC205 or Siglec-H. We show that despite a higher antigen load and faster receptor internalisation, when antigen is delivered to steady state or activated pDC via BST-2, BST-2-targeted activated conventional DCs present antigen more efficiently. Relative to DEC205, BST-2 was inferior in its capacity to deliver antigen to the MHCI cross-presentation pathway. In contrast, BST-2 was superior to Siglec-H at initiating either MHCI or MHCII antigen presentation. In summary, BST-2 is a useful receptor to target with antigen, given its broad expression pattern and ability to access both MHCI and MHCII presentation pathways with relative efficiency.
Related JoVE Video
Quantitative HBsAg and HBeAg predict hepatitis B seroconversion after initiation of HAART in HIV-HBV coinfected individuals.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
Anti-HBe seroconversion and HBsAg loss are important therapeutic endpoints in patients with hepatitis B virus (HBV) infection. Quantitative measures of hepatitis B surface antigen (qHBsAg) and e antigen (qHBeAg) have been identified as potentially useful indicators of therapeutic response in HBV monoinfection. The aim of this study was to examine serological change including quantitative biomarkers in HIV-HBV coinfected patients initiating HBV active antiretroviral therapy (ART).
Related JoVE Video
HDAC inhibitors in HIV.
Immunol. Cell Biol.
PUBLISHED: 11-15-2011
Show Abstract
Hide Abstract
Combination antiretroviral therapy (cART) has led to a very substantial reduction in morbidity and mortality in HIV-infected patients; however, cART alone is unable to cure HIV and therapy is lifelong. Therefore, a new strategy to cure HIV is urgently needed. There is now a concerted effort from scientists, clinicians and funding agencies to identify ways to achieve either a functional cure (long-term control of HIV in the absence of cART) or a sterilizing cure (elimination of all HIV-infected cells). Multiple strategies aiming at achieving a cure for HIV are currently being investigated, including both pharmacotherapy and gene therapy. In this review, we will review the rationale as well as in vitro and clinical trial data that support the role of histone deacetylase inhibitors as one approach to cure HIV.
Related JoVE Video
Viral adaptation to host immune responses occurs in chronic hepatitis B virus (HBV) infection, and adaptation is greatest in HBV e antigen-negative disease.
J. Virol.
PUBLISHED: 11-09-2011
Show Abstract
Hide Abstract
Hepatitis B virus (HBV)-specific T-cell responses are important in the natural history of HBV infection. The number of known HBV-specific T-cell epitopes is limited, and it is not clear whether viral evolution occurs in chronic HBV infection. We aimed to identify novel HBV T-cell epitopes by examining the relationship between HBV sequence variation and the human leukocyte antigen (HLA) type in a large prospective clinic-based cohort of Asian patients with chronic HBV infection recruited in Australia and China (n = 119). High-resolution 4-digit HLA class I and II typing and full-length HBV sequencing were undertaken for treatment-naïve individuals (52% with genotype B, 48% with genotype C, 63% HBV e antigen [HBeAg] positive). Statistically significant associations between HLA types and HBV sequence variation were identified (n = 49) at 41 sites in the HBV genome. Using prediction programs, we determined scores for binding between peptides containing these polymorphisms and associated HLA types. Among the regions that could be tested, HLA binding was predicted for 14/18 (78%). We identified several HLA-associated polymorphisms involving likely known anchor residues that resulted in altered predicted binding scores. Some HLA-associated polymorphisms fell within known T-cell epitopes with matching HLA restriction. Enhanced viral adaptation (defined as the presence of the relevant HLA and the escaped amino acid) was independently associated with HBeAg-negative disease (P = 0.003). Thus, HBV appears to be under immune pressure in chronic HBV infection, particularly in HBeAg-negative disease.
Related JoVE Video
CD4+ T-cell deficiency in HIV patients responding to antiretroviral therapy is associated with increased expression of interferon-stimulated genes in CD4+ T cells.
J. Infect. Dis.
PUBLISHED: 10-17-2011
Show Abstract
Hide Abstract
Most patients with human immunodeficiency virus (HIV) who remain CD4(+) T-cell deficient on antiretroviral therapy (ART) exhibit marked immune activation. As CD4(+) T-cell activation may be mediated by microbial translocation or interferon-alpha (IFN-?), we examined these factors in HIV patients with good or poor CD4(+) T-cell recovery on long-term ART. Messenger RNA levels for 3 interferon-stimulated genes were increased in CD4(+) T cells of patients with poor CD4(+) T-cell recovery, whereas levels in patients with good recovery did not differ from those in healthy controls. Poor CD4(+) T-cell recovery was also associated with CD4(+) T-cell expression of markers of activation, senescence, and apoptosis, and with increased serum levels of the lipopolysaccharide receptor and soluble CD14, but these were not significantly correlated with expression of the interferon-stimulated genes. Therefore, CD4(+) T-cell recovery may be adversely affected by the effects of IFN-?, which may be amenable to therapeutic intervention.
Related JoVE Video
Intensification of antiretroviral therapy with raltegravir or addition of hyperimmune bovine colostrum in HIV-infected patients with suboptimal CD4+ T-cell response: a randomized controlled trial.
J. Infect. Dis.
PUBLISHED: 09-19-2011
Show Abstract
Hide Abstract
Despite virally suppressive combination antiretroviral therapy (cART), some HIV-infected patients exhibit suboptimal CD4(+) T-cell recovery. This study aimed to determine the effect of intensification of cART with raltegravir or addition of hyperimmune bovine colostrum (HIBC) on CD4(+) T-cell count in such patients.
Related JoVE Video
HIV-1 predisposed to acquiring resistance to maraviroc (MVC) and other CCR5 antagonists in vitro has an inherent, low-level ability to utilize MVC-bound CCR5 for entry.
Retrovirology
PUBLISHED: 08-25-2011
Show Abstract
Hide Abstract
Maraviroc (MVC) and other CCR5 antagonists are HIV-1 entry inhibitors that bind to- and alter the conformation of CCR5, such that CCR5 is no longer recognized by the viral gp120 envelope (Env) glycoproteins. Resistance to CCR5 antagonists results from HIV-1 Env acquiring the ability to utilize the drug-bound conformation of CCR5. Selecting for HIV-1 resistance to CCR5-antagonists in vitro is relatively difficult. However, the CCR5-using CC1/85 strain appears to be uniquely predisposed to acquiring resistance to several CCR5 antagonists in vitro including MVC, vicriviroc and AD101.
Related JoVE Video
Expression and reactivation of HIV in a chemokine induced model of HIV latency in primary resting CD4+ T cells.
Retrovirology
PUBLISHED: 07-15-2011
Show Abstract
Hide Abstract
We recently described that HIV latent infection can be established in vitro following incubation of resting CD4+ T-cells with chemokines that bind to CCR7. The main aim of this study was to fully define the post-integration blocks to virus replication in this model of CCL19-induced HIV latency.
Related JoVE Video
Splenectomy associated changes in IgM memory B cells in an adult spleen registry cohort.
PLoS ONE
PUBLISHED: 07-13-2011
Show Abstract
Hide Abstract
Asplenic patients have a lifelong risk of overwhelming post-splenectomy infection and have been reported to have low numbers of peripheral blood IgM memory B cells. The clinical value of quantitation of memory B cells as an indicator of splenic abnormality or risk of infection has been unclear. To assess changes in B cell sub-populations after splenectomy we studied patients recruited to a spleen registry (n = 591). A subset of 209 adult asplenic or hyposplenic subjects, and normal controls (n = 140) were tested for IgM memory B cells. We also determined a) changes in IgM memory B cells with time after splenectomy using the cross-sectional data from patients on the registry and b) the kinetics of changes in haematological markers associated with splenectomy(n = 45). Total B cells in splenectomy patients did not differ from controls, but memory B cells, IgM memory B cells and switched B cells were significantly (p<0.001) reduced. The reduction was similar for different indications for splenectomy. Changes of asplenia in routine blood films including presence of Howell-Jolly bodies (HJB), occurred early (median 25 days) and splenectomy associated thrombocytosis and lymphocytosis peaked by 50 days. There was a more gradual decrease in IgM memory B cells reaching a stable level within 6 months after splenectomy. IgM memory B cells as proportion of B cells was the best discriminator between splenectomized patients and normal controls and at the optimal cut-off of 4.53, showed a true positive rate of 95% and false positive rate of 20%. In a survey of 152 registry patients stratified by IgM memory B cells around this cut-off there was no association with minor infections and no registry patients experienced OPSI during the study. Despite significant changes after splenectomy, conventional measures of IgM memory cells have limited clinical utility in this population.
Related JoVE Video
The role of naïve T-cells in HIV-1 pathogenesis: an emerging key player.
Clin. Immunol.
PUBLISHED: 07-08-2011
Show Abstract
Hide Abstract
Functional naïve T-cells are critical for an effective immune response to multiple pathogens. HIV leads to a significant reduction in CD4+ naïve T-cell number and impaired function and there is incomplete recovery following combination antiretroviral therapy (cART). Here we review the basic homeostatic mechanisms that maintain naïve CD4+ T-cells and discuss recent developments in understanding the impact of HIV infection on naïve CD4+ T-cells. Finally we review therapeutic interventions in HIV-infected individuals aimed at specifically enhancing recovery of naïve CD4+ T-cells.
Related JoVE Video
Factors associated with elevated ALT in an international HIV/HBV co-infected cohort on long-term HAART.
PLoS ONE
PUBLISHED: 06-07-2011
Show Abstract
Hide Abstract
Previous studies have demonstrated that hepatitis B virus (HBV) infection increases the risk for ALT elevations in HIV-HBV co-infected patients during the first year of HAART; however, there is limited data on the prevalence of ALT elevations with prolonged HAART in this patient group.
Related JoVE Video
Thymic plasmacytoid dendritic cells are susceptible to productive HIV-1 infection and efficiently transfer R5 HIV-1 to thymocytes in vitro.
Retrovirology
PUBLISHED: 06-03-2011
Show Abstract
Hide Abstract
HIV-1 infection of the thymus contributes to the defective regeneration and loss of CD4+ T cells in HIV-1-infected individuals. As thymic dendritic cells (DC) are permissive to infection by HIV-1, we examined the ability of thymic DC to enhance infection of thymocytes which may contribute to the overall depletion of CD4+ T cells. We compared productive infection in isolated human thymic and blood CD11c+ myeloid DC (mDC) and CD123+ plasmacytoid DC (pDC) using enhanced green fluorescent protein (EGFP) CCR5 (R5)-tropic NL(AD8) and CXCR4 (X4)-tropic NL4-3 HIV-1 reporter viruses. Transfer of productive HIV-1 infection from thymic mDC and pDC was determined by culturing these DC subsets either alone or with sorted thymocytes.
Related JoVE Video
Antibody and B-cell responses may control circulating lipopolysaccharide in patients with HIV infection.
AIDS
PUBLISHED: 05-17-2011
Show Abstract
Hide Abstract
To examine the relationship between plasma markers of microbial translocation and antibodies to lipopolysaccharide (LPS) and circulating memory B cells in patients with HIV infection.
Related JoVE Video
Clinical predictors of immune reconstitution following combination antiretroviral therapy in patients from the Australian HIV Observational Database.
PLoS ONE
PUBLISHED: 05-08-2011
Show Abstract
Hide Abstract
A small but significant number of patients do not achieve CD4 T-cell counts >500 cells/µl despite years of suppressive cART. These patients remain at risk of AIDS and non-AIDS defining illnesses. The aim of this study was to identify clinical factors associated with CD4 T-cell recovery following long-term cART.
Related JoVE Video
Increased intrahepatic apoptosis but reduced immune activation in HIV-HBV co-infected patients with advanced immunosuppression.
AIDS
PUBLISHED: 05-07-2011
Show Abstract
Hide Abstract
to determine if intrahepatic immune activation is increased in HIV-hepatitis B virus (HBV) co-infected patients compared to HBV mono-infected patients and whether this reduced following HBV-active antiretroviral therapy (ART) in HIV-HBV co-infected patients.
Related JoVE Video
Differential expression of CD163 on monocyte subsets in healthy and HIV-1 infected individuals.
PLoS ONE
PUBLISHED: 04-19-2011
Show Abstract
Hide Abstract
CD163, a haptoglobin-hemoglobin (Hp-Hb) scavenger receptor, expressed by monocytes and macrophages, is important in resolution of inflammation. Age-related non-AIDS co-morbidities in HIV-infected individuals, particularly dementia and cardiovascular disease, result in part from effects of HIV-1 infection on monocyte and macrophage biology. CD163 co-expression on CD14+CD16++ monocytes has been proposed as a useful biomarker for HIV-1 disease progression and the presence of HIV associated dementia. Here we investigated CD163 expression on monocyte subsets ex vivo, on cultured macrophages, and soluble in plasma, in the setting of HIV-1 infection. Whole blood immunophenotyping revealed CD163 expression on CD14++CD16- monocytes but not on CD14+CD16++ monocytes (P?=?0.004), supported by CD163 mRNA levels. Incubation with M-CSF induced CD163 protein expression on CD14+CD16++ monocytes to the same extent as CD14++CD16- monocytes. CD163 expression on CD14++CD16+ monocytes from HIV-infected subjects was significantly higher than from uninfected individuals, with a trend towards increased expression on CD14++CD16- monocytes (P?=?0.019 and 0.069 respectively), which is accounted for by HIV-1 therapy including protease inhibitors. Shedding of CD163 was shown to predominantly occur from the CD14++CD16- subset after Ficoll isolation and LPS stimulation. Soluble CD163 concentration in plasma from HIV-1 infected donors was similar to HIV-1 uninfected donors. Monocyte CD163 expression in HIV-1 infected patients showed a complicated relationship with classical measures of disease progression. Our findings clarify technical issues regarding CD163 expression on monocyte subsets and further elucidates its role in HIV-associated inflammation by demonstrating that CD163 is readily lost from CD14++CD16- monocytes and induced in pro-inflammatory CD14+CD16++ monocytes by M-CSF. Our data show that all monocyte subsets are potentially capable of differentiating into CD163-expressing anti-inflammatory macrophages given appropriate stimuli. Levels of CD163 expression on monocytes may be a potential biomarker reflecting efforts by the immune system to resolve immune activation and inflammation in HIV-infected individuals.
Related JoVE Video
Biomarkers of immune dysfunction following combination antiretroviral therapy for HIV infection.
Biomark Med
PUBLISHED: 04-09-2011
Show Abstract
Hide Abstract
Combination antiretroviral therapy (cART) has significantly reduced morbidity and mortality of HIV-infected patients, yet their life expectancy remains reduced compared with the general population. Most HIV-infected patients receiving cART have some persistent immune dysfunction characterized by chronic immune activation and premature aging of the immune system. Here we review biomarkers of T-cell activation (CD69, -25 and -38, HLA-DR, and soluble CD26 and -30); generalized immune activation (C-reactive protein, IL-6 and D-dimer); microbial translocation (lipopolysaccharide, 16S rDNA, lipopolysaccharide-binding protein and soluble CD14); and immune dysfunction of specific cellular subsets (T cells, natural killer cells and monocytes) in HIV-infected patients on cART and their relationship to adverse clinical outcomes including impaired CD4 T-cell recovery, as well as non-AIDS clinical events, such as cardiovascular disease.
Related JoVE Video
HIV cure and eradication: how will we get from the laboratory to effective clinical trials?
AIDS
PUBLISHED: 03-23-2011
Show Abstract
Hide Abstract
Combination antiretroviral therapy (cART) has led to a major reduction in HIV-related mortality and morbidity; however, HIV can still not be cured. Achieving either a functional cure (long-term control of HIV in the absence of cART) or a sterilizing cure (elimination of all HIV-infected cells) remains a major challenge. The most significant barrier to cure is the establishment of a latent or silent infection in resting CD4 T cells. Several randomized clinical trials have demonstrated that treatment intensification with additional antiretrovirals has little impact on latent reservoirs. Some potential other approaches that may reduce the latent reservoir include very early initiation of cART and the use of agents that could reverse latent infection. Drugs such as histone deacetylase inhibitors, currently used and licensed for the treatment of some cancers; methylation inhibitors; cytokines such as IL-7 or activators of nuclear factor kappa B (NF-?B) such as prostratin, show promising activity in reversing latency in vitro when used either alone or in combination. Alternate strategies include using gene therapy to modify expression of CCR5 and therefore make cells resistant to HIV. This review will primarily focus on the advantages and disadvantages of methods currently being used to quantify persistent virus ex vivo in patients receiving cART and strategies aimed at cure that are being tested in vitro or in early clinical development. In addition, we discuss key issues that need to be addressed to successfully move laboratory research to clinical trials aimed at curing HIV.
Related JoVE Video
HIV-1 escape from the CCR5 antagonist maraviroc associated with an altered and less-efficient mechanism of gp120-CCR5 engagement that attenuates macrophage tropism.
J. Virol.
PUBLISHED: 02-23-2011
Show Abstract
Hide Abstract
Maraviroc (MVC) inhibits the entry of human immunodeficiency virus type 1 (HIV-1) by binding to and modifying the conformation of the CCR5 extracellular loops (ECLs). Resistance to MVC results from alterations in the HIV-1 gp120 envelope glycoproteins (Env) enabling recognition of the drug-bound conformation of CCR5. To better understand the mechanisms underlying MVC resistance, we characterized the virus-cell interactions of gp120 from in vitro-generated MVC-resistant HIV-1 (MVC-Res Env), comparing them with those of gp120 from the sensitive parental virus (MVC-Sens Env). In the absence of the drug, MVC-Res Env maintains a highly efficient interaction with CCR5, similar to that of MVC-Sens Env, and displays a relatively modest increase in dependence on the CCR5 N terminus. However, in the presence of the drug, MVC-Res Env interacts much less efficiently with CCR5 and becomes critically dependent on the CCR5 N terminus and on positively charged elements of the drug-modified CCR5 ECL1 and ECL2 regions (His88 and His181, respectively). Structural analysis suggests that the Val323 resistance mutation in the gp120 V3 loop alters the secondary structure of the V3 loop and the buried surface area of the V3 loop-CCR5 N terminus interface. This altered mechanism of gp120-CCR5 engagement dramatically attenuates the entry of HIV-1 into monocyte-derived macrophages (MDM), cell-cell fusion activity in MDM, and viral replication capacity in MDM. In addition to confirming that HIV-1 escapes MVC by becoming heavily dependent on the CCR5 N terminus, our results reveal novel interactions with the drug-modified ECLs that are critical for the utilization of CCR5 by MVC-Res Env and provide additional insights into virus-cell interactions that modulate macrophage tropism.
Related JoVE Video
Early events of HIV-1 infection: can signaling be the next therapeutic target?
J Neuroimmune Pharmacol
PUBLISHED: 01-24-2011
Show Abstract
Hide Abstract
Intracellular signaling events are signposts of biological processes, which govern the direction and action of biological activities. Through millions of years of evolution, pathogens, such as viruses, have evolved to hijack host cell machinery to infect their targets and are therefore dependent on host cell signaling for replication. This review will detail our current understanding of the signaling events that are important for the early steps of HIV-1 replication. More specifically, the therapeutic potential of signaling events associated with chemokine coreceptors, virus entry, viral synapses, and post-entry processes will be discussed. We argue that these pathways may represent novel targets for antiviral therapy.
Related JoVE Video
Finding a cure for HIV: will it ever be achievable?
J Int AIDS Soc
PUBLISHED: 01-24-2011
Show Abstract
Hide Abstract
Combination antiretroviral therapy (cART) has led to a major reduction in HIV-related mortality and morbidity. However, HIV still cannot be cured. With the absence of an effective prophylactic or therapeutic vaccine, increasing numbers of infected people, emerging new toxicities secondary to cART and the need for life-long treatment, there is now a real urgency to find a cure for HIV.There are currently multiple barriers to curing HIV. The most significant barrier is the establishment of a latent or "silent" infection in resting CD4+ T cells. In latent HIV infection, the virus is able to integrate into the host cell genome, but does not proceed to active replication. As a consequence, antiviral agents, as well as the immune system, are unable to eliminate these long-lived, latently infected cells. Reactivation of latently infected resting CD4+ T cells can then re-establish infection once cART is stopped. Other significant barriers to cure include residual viral replication in patients receiving cART, even when the virus is not detectable by conventional assays. In addition, HIV can be sequestered in anatomical reservoirs, such as the brain, gastrointestinal tract and genitourinary tract.Achieving either a functional cure (long-term control of HIV in the absence of cART) or a sterilizing cure (elimination of all HIV-infected cells) remains a major challenge. Several studies have now demonstrated that treatment intensification appears to have little impact on latent reservoirs. Some potential and promising approaches that may reduce the latent reservoir include very early initiation of cART and the use of agents that could potentially reverse latent infection.Agents that reverse latent infection will promote viral production; however, simultaneous administration of cART will prevent subsequent rounds of viral replication. Such drugs as histone deacetylase inhibitors, currently used and licensed for the treatment of some cancers, or activating latently infected resting cells with cytokines, such as IL-7 or prostratin, show promising results in reversing latency in vitro when used either alone or in combination. In order to move forward toward clinical trials that target eradication, there needs to be careful consideration of the risks and benefits of these approaches, agreement on the most informative endpoints for eradication studies and greater engagement of the infected community.
Related JoVE Video
Plasma levels of soluble CD14 independently predict mortality in HIV infection.
J. Infect. Dis.
PUBLISHED: 01-20-2011
Show Abstract
Hide Abstract
Chronic human immunodeficiency virus (HIV) infection is associated with intestinal permeability and microbial translocation that contributes to systemic immune activation, which is an independent predictor of HIV disease progression. The association of microbial translocation with clinical outcome remains unknown.
Related JoVE Video
Pharmacy adherence measures to assess adherence to antiretroviral therapy: review of the literature and implications for treatment monitoring.
Clin. Infect. Dis.
PUBLISHED: 01-18-2011
Show Abstract
Hide Abstract
Prescription or pill-based methods for estimating adherence to antiretroviral therapy (ART), pharmacy adherence measures (PAMs), are objective estimates calculated from routinely collected pharmacy data. We conducted a literature review to evaluate PAMs, including their association with virological and other clinical outcomes, their efficacy compared with other adherence measures, and factors to consider when selecting a PAM to monitor adherence. PAMs were classified into 3 categories: medication possession ratio (MPR), pill count (PC), and pill pick-up (PPU). Data exist to recommend PAMs over self-reported adherence. PAMs consistently predicted patient outcomes, but additional studies are needed to determine the most predictive PAM parameters. Current evidence suggests that shorter duration of adherence assessment (? 6 months) and use of PAMs to predict future outcomes may be less accurate. PAMs which incorporate the number of days for which ART was prescribed without the counting of remnant pills, are reasonable minimum-resource methods to assess adherence to ART.
Related JoVE Video
Balamuthia mandrillaris brain abscess successfully treated with complete surgical excision and prolonged combination antimicrobial therapy.
J. Neurosurg.
PUBLISHED: 11-12-2010
Show Abstract
Hide Abstract
Amoebic encephalitis is an uncommon and usually fatal condition. This case describes successful treatment of a Balamuthia mandrillaris brain abscess using prolonged antimicrobial agents with complete excision. It illustrates the risk of dissemination from cutaneous to cerebral amoebic lesions, potential progression with corticosteroid therapy, and the prospect for curative excision.
Related JoVE Video
Both CD31(+) and CD31? naive CD4(+) T cells are persistent HIV type 1-infected reservoirs in individuals receiving antiretroviral therapy.
J. Infect. Dis.
PUBLISHED: 10-27-2010
Show Abstract
Hide Abstract
Naive T cell recovery is critical for successful immune reconstitution after antiretroviral therapy (ART), but the relative contribution of CD31(+) and CD31? naive T cells to immune reconstitution and viral persistence is unknown.
Related JoVE Video
HIV inhibits early signal transduction events triggered by CD16 cross-linking on NK cells, which are important for antibody-dependent cellular cytotoxicity.
J. Leukoc. Biol.
PUBLISHED: 09-30-2010
Show Abstract
Hide Abstract
Measurement of NK cell cytolytic activity in the setting of chronic viral infection is important for determining viral pathogenicity. Mobilization of LAMP-1 (CD107a) to the NK cell surface is a surrogate marker for cytotoxic granule release and hence, NK cell cytotoxicity. We have developed a convenient, rapid, whole blood flow cytometric assay for measuring CD107a mobilization in response to CD16 cross-linking, a surrogate for NK cell ADCC activity ex vivo, which can be performed using small volumes of patient whole blood. Using this assay, we show that CD107a mobilization, in response to CD16 cross-linking, is triggered in CD56(dim) but not CD56(bright) NK cells, requiring Syk/Zap70 tyrosine kinase activity, and that there is a significant correlation between CD107a mobilization and pSyk/Zap70 in response to CD16 cross-linking. We compared whole blood from treatment-naïve, HIV-infected patients with age- and sex-matched HIV-uninfected control subjects and found a significant reduction in CD16-dependent pSyk/Zap70 (median=32.7% compared with 67.8%; P=0.0002) and CD107a mobilization (median=9.72% compared with 32.9%; P=0.046) in NK cells. Reduction of both correlated strongly with reduced CD16 surface expression on NK cells of HIV-infected individuals (P<0.01). These data suggest that ADCC is inhibited in NK cells from therapy-naïve, HIV-infected individuals at the level of early events in CD16 signal transduction, associated with low CD16R expression, and our method is a useful and reliable tool to detect pathological defects in NK cell degranulation.
Related JoVE Video
Efficacy of tenofovir disoproxil fumarate/emtricitabine compared with emtricitabine alone in antiretroviral-naive HIV-HBV coinfection in Thailand.
Antivir. Ther. (Lond.)
PUBLISHED: 09-14-2010
Show Abstract
Hide Abstract
Therapy for chronic hepatitis B with tenofovir disoproxil fumarate (TDF) and lamivudine (3TC) or emtricitabine (FTC) is currently recommended for HIV-HBV coinfection. However, there is limited randomized data on the efficacy of combined therapy with TDF and FTC, especially in antiretroviral (ARV)-naive patients.
Related JoVE Video
Establishment of HIV-1 latency in resting CD4+ T cells depends on chemokine-induced changes in the actin cytoskeleton.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 09-13-2010
Show Abstract
Hide Abstract
Eradication of HIV-1 with highly active antiretroviral therapy (HAART) is not possible due to the persistence of long-lived, latently infected resting memory CD4(+) T cells. We now show that HIV-1 latency can be established in resting CD4(+) T cells infected with HIV-1 after exposure to ligands for CCR7 (CCL19), CXCR3 (CXCL9 and CXCL10), and CCR6 (CCL20) but not in unactivated CD4(+) T cells. The mechanism did not involve cell activation or significant changes in gene expression, but was associated with rapid dephosphorylation of cofilin and changes in filamentous actin. Incubation with chemokine before infection led to efficient HIV-1 nuclear localization and integration and this was inhibited by the actin stabilizer jasplakinolide. We propose a unique pathway for establishment of latency by direct HIV-1 infection of resting CD4(+) T cells during normal chemokine-directed recirculation of CD4(+) T cells between blood and tissue.
Related JoVE Video
Biological determinants of immune reconstitution in HIV-infected patients receiving antiretroviral therapy: the role of interleukin 7 and interleukin 7 receptor ? and microbial translocation.
J. Infect. Dis.
PUBLISHED: 09-04-2010
Show Abstract
Hide Abstract
Multiple host factors may influence CD4(+) T cell reconstitution in human immunodeficiency virus (HIV)-infected patients after suppressive antiretroviral therapy (ART). We hypothesized that residual immune activation and polymorphisms in the interleukin 7 (IL-7) receptor ? (IL-7R?) gene were important for immune recovery.
Related JoVE Video
Serum hepatitis B surface antigen and hepatitis B e antigen titers: disease phase influences correlation with viral load and intrahepatic hepatitis B virus markers.
Hepatology
PUBLISHED: 06-01-2010
Show Abstract
Hide Abstract
Although threshold levels for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) titers have recently been proposed to guide therapy for chronic hepatitis B (CHB), their relationship to circulating hepatitis B virus (HBV) DNA and intrahepatic HBV replicative intermediates, and the significance of emerging viral variants, remains unclear. We therefore tested the hypothesis that HBsAg and HBeAg titers may vary independently of viral replication in vivo. In all, 149 treatment-naïve CHB patients were recruited (HBeAg-positive, n = 71; HBeAg-negative, n = 78). Quantification of HBeAg and HBsAg was performed by enzyme immunoassay. Virological characterization included serum HBV DNA load, HBV genotype, basal core promoter (BCP)/precore (PC) sequence, and, in a subset (n = 44), measurement of intrahepatic covalently closed circular DNA (cccDNA) and total HBV DNA, as well as quantitative immunohistochemical (IHC) staining for HBsAg. In HBeAg-positive CHB, HBsAg was positively correlated with serum HBV DNA and intrahepatic cccDNA and total HBV DNA (r = 0.69, 0.71, 0.76, P < 0.01). HBeAg correlated with serum HBV DNA (r = 0.60, P < 0.0001), although emerging BCP/PC variants reduced HBeAg titer independent of viral replication. In HBeAg-negative CHB, HBsAg correlated poorly with serum HBV DNA (r = 0.28, P = 0.01) and did not correlate with intrahepatic cccDNA nor total HBV DNA. Quantitative IHC for hepatocyte HBsAg confirmed a relationship with viral replication only in HBeAg-positive patients.
Related JoVE Video
Extremely prolonged HIV seroconversion associated with an MHC haplotype carrying disease susceptibility genes for antibody deficiency disorders.
Clin. Immunol.
PUBLISHED: 05-11-2010
Show Abstract
Hide Abstract
Severe immunodeficiency during primary human immunodeficiency virus (HIV) infection is unusual. Here, we characterized viral and immunological parameters in a subject presenting with Pneumocystis jirovecii pneumonia in the setting of prolonged primary HIV illness and delayed seroconversion. HIV antibody was only detected by enzyme-linked immunosorbent assay 12 months after presentation, and Western blot profiles remain indeterminate. Isolated virus was of R5 phenotype, exhibited poor viral fitness, but was otherwise unremarkable. Analysis of HIV antibody isotypes showed failure to mount a detectable HIV IgG response over nearly 2 years of infection, in particular IgG(1)- and IgG(3)-specific responses, despite normal responses to common infections and vaccines. Genetic analysis demonstrated homozygosity for part of an MHC haplotype containing susceptibility genes for common variable immunodeficiency (CVID) syndrome and other antibody deficiency disorders. Thus, a primary disorder of specific antibody production may explain exceptionally slow antibody development in an otherwise severe seroconversion illness. This highlights the need for multiparameter testing, in particular use of a fourth generation HIV test, for confirming HIV infection and underscores the importance of host factors in HIV pathogenesis.
Related JoVE Video
Coinfection of hepatic cell lines with human immunodeficiency virus and hepatitis B virus leads to an increase in intracellular hepatitis B surface antigen.
J. Virol.
PUBLISHED: 03-31-2010
Show Abstract
Hide Abstract
Liver-related mortality is increased in the setting of HIV-hepatitis B virus (HBV) coinfection. However, interactions between HIV and HBV to explain this observation have not been described. We hypothesized that HIV infection of hepatocytes directly affects the life cycle of HBV. We infected human hepatic cell lines expressing HBV (Hep3B and AD38 cells) or not expressing HBV (Huh7, HepG2, and AD43 cells) with laboratory strains of HIV (NL4-3 and AD8), as well as a vesicular stomatitis virus (VSV)-pseudotyped HIV expressing enhanced green fluorescent protein (EGFP). Following HIV infection with NL4-3 or AD8 in hepatic cell lines, we observed a significant increase in HIV reverse transcriptase activity which was infectious. Despite no detection of surface CD4, CCR5, and CXCR4 by flow cytometry, AD8 infection of AD38 cells was inhibited by maraviroc and NL4-3 was inhibited by AMD3100, demonstrating that HIV enters AD38 hepatic cell lines via CCR5 or CXCR4. High-level infection of AD38 cells (50%) was achieved using VSV-pseudotyped HIV. Coinfection of the AD38 cell line with HIV did not alter the HBV DNA amount or species as determined by Southern blotting or nucleic acid signal amplification. However, coinfection with HIV was associated with a significant increase in intracellular HBsAg when measured by Western blotting, quantitative HBsAg, and fluorescence microscopy. We conclude that HIV infection of HBV-infected hepatic cell lines significantly increased intracellular HBsAg but not HBV DNA synthesis and that increased intrahepatic HBsAg secondary to direct infection by HIV may contribute to accelerated liver disease in HIV-HBV-coinfected individuals.
Related JoVE Video
HBV mutations in untreated HIV-HBV co-infection using genomic length sequencing.
Virology
PUBLISHED: 03-09-2010
Show Abstract
Hide Abstract
HIV infection has a significant impact on the natural progression of hepatitis B virus (HBV) related liver disease. In HIV-HBV co-infected patients, little is known about mutations in the HBV genome, which can influence severity of liver disease. The aim of this study was to characterize and to determine the frequency of known clinically significant mutations in the HBV genomes from HIV-HBV co-infected patients and from HBV mono-infected patients. To accomplish this, genomic length HBV sequencing was performed in highly-active anti-retroviral therapy (HAART)-naïve HIV-HBV co-infected patients (n=74) and in anti-HBV therapy-naïve HBV mono-infected patients (n=55). The frequency of HBV mutations differed between the co-infected and mono-infected patients when comparing patients with the same genotype. BCP mutations A1762T and G1764A were significantly more frequent in HBV genotype C mono-infection and the -1G frameshift was significantly more frequent in co-infection and was only observed in HBV genotype A co-infection. PreS2 deletions were observed more frequently in the setting of co-infection. Further work is needed to determine if these mutational patterns influence the differences in liver disease progression in HIV-HBV co-infected and HBV mono-infected patients.
Related JoVE Video
Decreased NK Cell FcRgamma in HIV-1 infected individuals receiving combination antiretroviral therapy: a cross sectional study.
PLoS ONE
PUBLISHED: 01-28-2010
Show Abstract
Hide Abstract
FcRgamma is an immunoreceptor tyrosine-based activation motif (ITAM)-signalling protein essential for immunoreceptor signaling and monocyte, macrophage and NK cell function. Previous study from our laboratory showed that FcRgamma is down-regulated in HIV-infected macrophages in vitro. FcRgamma expression in immune cells present in HIV-infected individuals is unknown.
Related JoVE Video
A novel, rapid method to detect infectious HIV-1 from plasma of persons infected with HIV-1.
J. Virol. Methods
PUBLISHED: 01-19-2010
Show Abstract
Hide Abstract
Efficient isolation of replication-competent virus from plasma of patients infected with HIV-1 is needed to characterize important clinical parameters of virus. However, addition of plasma to in vitro cultures results in clot formation. Blood from HIV-1 infected patients was collected in the presence of three commonly used anticoagulants (ACD, heparin and EDTA) and plasma was isolated. Plasma was then used to infect HIV-1 indicator cell lines (TZM-bl and GHOST) with spinoculation in the presence or absence of additional heparin and positively charged polymers. The presence of additional heparin during inoculation significantly reduced clot formation without affecting the sensitivity of HIV-1 infection in the GHOST cell line. However, heparin reduced the frequency of HIV-1 infection of the TZM-bl cell line. Using plasma from patients with HIV RNA>1000 copies/ml (n=58), the frequency of HIV-1 isolation was 92% in GHOST (n=51) and 54% in TZM-bl (n=26) cell lines. A sensitive method was developed for rapid isolation of infectious HIV-1 from plasma of patients with HIV RNA>1000 copies/ml that includes spinoculation and the addition of heparin during infection of GHOST cells. This technique could be used for rapid evaluation of viral fitness, co-receptor usage or drug resistance without the need for viral amplification.
Related JoVE Video
No increase in hepatitis B virus (HBV)-specific CD8+ T cells in patients with HIV-1-HBV coinfections following HBV-active highly active antiretroviral therapy.
J. Virol.
PUBLISHED: 01-06-2010
Show Abstract
Hide Abstract
Following treatment of hepatitis B virus (HBV) monoinfection, HBV-specific T-cell responses increase significantly; however, little is known about the recovery of HBV-specific T-cell responses following HBV-active highly active antiretroviral therapy (HAART) in HIV-HBV coinfected patients. HIV-HBV coinfected patients who were treatment naïve and initiating HBV-active HAART were recruited as part of a prospective cohort study in Thailand and followed for 48 weeks (n = 24). Production of gamma interferon (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) in both HBV- and HIV-specific CD8(+) T cells was quantified using intracellular cytokine staining on whole blood. Following HBV-active HAART, the median (interquartile range) log decline from week 0 to week 48 for HBV DNA was 5.8 log (range, 3.4 to 6.7) IU/ml, and for HIV RNA it was 3.1 (range, 2.9 to 3.5) log copies/ml (P < 0.001 for both). The frequency of HIV Gag-specific CD8(+) T-cell responses significantly decreased (IFN-gamma, P < 0.001; TNF-alpha, P = 0.05). In contrast, there was no significant change in the frequency (IFN-gamma, P = 0.21; TNF-alpha, P = 0.61; and IFN-gamma and TNF-alpha, P = 0.11) or magnitude (IFN-gamma, P = 0.13; TNF-alpha, P = 0.13; and IFN-gamma and TNF-alpha, P = 0.13) of HBV-specific CD8(+) T-cell responses over 48 weeks of HBV-active HAART. Of the 14 individuals who were HBV e antigen (HBeAg) positive, 5/14 (36%) lost HBeAg during the 48 weeks of follow-up. HBV-specific CD8(+) T cells were detected in 4/5 (80%) of patients prior to HBeAg loss. Results from this study show no sustained change in the HBV-specific CD8(+) T-cell response following HBV-active HAART. These findings may have implications for the duration of treatment of HBV in HIV-HBV coinfected patients, particularly in HBeAg-positive disease.
Related JoVE Video
The "work" of women when considering and using interventions to reduce mother-to-child transmission (MTCT) of HIV.
AIDS Care
PUBLISHED: 12-22-2009
Show Abstract
Hide Abstract
This paper explores HIV-infected womens experiences of considering and using recommended interventions during pregnancy and postpartum to reduce mother-to-child transmission of HIV. Data were collected from 45 HIV-infected women aged 18-44 years living in Melbourne, Australia. A semi-structured interview was used to collect qualitative information on womens reproductive experience and intentions. The 15 women who had their children after their HIV diagnosis engaged in significant work including surveillance and safety work to minimise stigma and infection, information work to inform decisions and actions, accounting work to calculate risk and benefit, hope and worry work concerning a childs infection status and impact of interventions, work to redefine an acceptable maternal identity, work to prepare an alternative story to counter the disclosure effect of the intervention and emotional work to reconcile guilt when considering these interventions. This study provides a framework to help clinicians understand the real and on-going "work" that women engage in when they are considering interventions recommended by their physicians to reduce transmission of HIV. Even in circumstances where access to and acceptance of interventions are high, women continue to engage in this work even after they have a made a decision about a particular intervention.
Related JoVE Video
Future directions in the treatment of HIV-HBV coinfection.
HIV Ther
PUBLISHED: 11-16-2009
Show Abstract
Hide Abstract
Liver disease is a major cause of mortality in individuals with HIV-HBV coinfection. The pathogenesis of liver disease in this setting is unknown, but is likely to involve drug toxicity, infection of hepatic cells with both HIV and HBV, and an altered immune response to HBV. The availability of therapeutic agents that target both HIV and HBV replication enable dual viral suppression, and assessment of chronic hepatitis B is important prior to commencement of antiretroviral therapy. Greater importance is now placed on HBV DNA levels and staging of liver fibrosis, either by liver biopsy or noninvasive measurement, such as transient elastography, since significant liver fibrosis may exist in the presence of normal liver function tests. Earlier treatment of both HIV and HBV is now generally advocated and treatment is usually lifelong.
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.