Attack by multiple herbivores often leads to modification of induced plant defenses compared to single herbivory, yet little is known about the effects on induced indirect plant defense. Here, we investigated the effect of sequential induction of plant defense by Mamestra brassicae caterpillar oral secretion and an infestation by Tetranychus urticae spider mites on the expression of indirect plant defense in Lima bean plants. The effect on indirect defense was assessed using behavior assays with the specialist predatory mite Phytoseiulus persimilis in an olfactometer, headspace analysis of 11 major herbivore-induced plant volatiles (HIPVs) including (E)-?-ocimene, and transcript levels of the corresponding gene Phaseolus lunatus (E)-?-ocimene synthase (PlOS). Predatory mites were found to distinguish between plants induced by spider mites and caterpillar oral secretion but not between plants with single spider mite infestation and plants induced by caterpillar oral secretion prior to spider mite infestation. Indeed, the volatile blends emitted by plants induced by spider mites only and the sequential induction treatment of caterpillar oral secretion followed by spider mite infestation, were similar. Our results suggest that plant indirect defense is not affected by previous treatment with oral secretion of M. brassicae caterpillars.
Adenomyosis is an oestrogen-dependent disease characterized by the invasion of endometrial epithelial cells into the myometrium of uterus, and angiogenesis is thought to be required for the implantation of endometrial glandular tissues during the adenomyotic pathogenesis. In this study, we demonstrate that compared with eutopic endometria, adenomyotic lesions exhibited increased vascularity as detected by sonography. Microscopically, the lesions also exhibited an oestrogen-associated elevation of microvascular density and VEGF expression in endometrial epithelial cells. We previously reported that oestrogen-induced Slug expression was critical for endometrial epithelial-mesenchymal transition and development of adenomyosis. Our present studies demonstrated that estradiol (E2) elicited a Slug-VEGF axis in endometrial epithelial cells, and also induced pro-angiogenic activity in vascular endothelial cells. The antagonizing agents against E2 or VEGF suppressed endothelial cells migration and tubal formation. Animal experiments furthermore confirmed that blockage of E2 or VEGF was efficient to attenuate the implantation of adenomyotic lesions. These results highlight the importance of oestrogen-induced angiogenesis in adenomyosis development and provide a potential strategy for treating adenomyosis through intercepting the E2-Slug-VEGF pathway.
Elevated macrophage infiltration in tumor tissues is associated with breast cancer metastasis. Cancer cell migration/invasion toward angiogenic microvasculature is a key step in metastatic spread. We therefore studied how macrophages stimulated breast cancer cell interactions with endothelial cells. Macrophages produced cytokines, such as interleukin-8 and tumor necrosis factor-?, to stimulate endothelin (ET) and ET receptor (ETR) expression in breast cancer cells and human umbilical vascular endothelial cells (HUVECs). ET-1 was induced to a greater extent from HUVECs than from breast cancer cells, resulting in a density difference that facilitated cancer cell chemotaxis toward HUVECs. Macrophages also stimulated breast cancer cell adhesion to HUVECs and transendothelial migration, which were repressed by ET-1 antibody or ETR inhibitors. The ET axis induced integrins, such as ?V and ?1, and their counterligands, such as intercellular adhesion molecule-2 and P-selectin, in breast cancer cells and HUVECs, and antibodies against these integrins efficiently suppressed macrophage-stimulated breast cancer cell interactions with HUVECs. ET-1 induced Ets-like kinase-1 (Elk-1), signal transducer and activator of transcription-3 (STAT-3), and nuclear factor-?B (NF-?B) phosphorylation in breast cancer cells. The use of inhibitors to prevent their phosphorylation or ectopic overexpression of dominant-negative I?B? perturbed ET-1-induced integrin ?V and integrin ?1 expression. The physical associations of these three transcriptional factors with the gene promoters of the two integrins were furthermore evidenced by a chromatin immunoprecipitation assay. Finally, our mouse orthotopic tumor model revealed an ET axis-mediated lung metastasis of macrophage-stimulated breast cancer cells, suggesting that the ET axis was involved in macrophage-enhanced breast cancer cell endothelial interactions.
DNA hypermethylation of promoter CpG islands is associated with epigenetic silencing of tumor suppressor genes in oral squamous cell carcinomas (OSCCs). We used a methyl-CpG-binding domain protein capture method coupled with next-generation sequencing (MBDCap-seq) to survey global DNA methylation patterns in OSCCs with and without nodal metastasis and normal mucosa (total n = 58). Of 1462 differentially methylated CpG islands identified in OSCCs relative to normal controls, MBDCap-seq profiling uncovered 359 loci linked to lymph node metastasis. Interactive network analysis revealed a subset of these loci (n = 23), including the anaplastic lymphoma kinase (ALK) gene, are potential regulators and effectors of invasiveness and metastatic progression. Promoter methylation of ALK was preferentially observed in OSCCs without node metastasis, whereas relatively lower methylation levels were present in metastatic tumors, implicating an active state of ALK transcription in the latter group. The OSCC cell line, SCC4, displayed reduced ALK expression that corresponded to extensive promoter CpG island methylation. SCC4 treatment with demethylating agents induced ALK expression and increased invasion and migration characteristics. Inhibition of ALK activity in OSCC cells with high ALK expression (CAL27, HSC3 and SCC25), decreased cell growth and resulted in changes in invasive potential and mesenchymal marker expression that were cell-line dependent. Although ALK is susceptible to epigenetic silencing during oral tumorigenesis, overwriting this default state may be necessary for modulating invasive processes involved in nodal metastases. Given the complex response of OSCC cells to ALK inhibition, future studies are required to assess the feasibility of targeting ALK to treat invasive OSCCs.
Seasonal and novel influenza infections have the potential to cause worldwide pandemics. In order to properly treat infected patients and to limit its spread, a rapid, accurate and automatic influenza diagnostic tool needs to be developed. This study therefore presents a new integrated microfluidic system for the rapid detection of influenza infections. It integrated a suction-type, pneumatic-driven microfluidic control module, a magnetic bead-based fluorescent immunoassay (FIA) and an end-point optical detection module. This new system can successfully distinguish between influenza A and B using a single chip test within 15 min automatically, which is faster than existing devices. By utilizing the micromixers to thoroughly wash out the sputum-like mucus, this microfluidic system could be used for the diagnosis of clinical specimens and reduced the required sample volume to 40 ?L. Furthermore, the results of diagnostic assays from 86 patient specimens have demonstrated that this system has 84.8 % sensitivity and 75.0 % specificity. This developed system may provide a powerful platform for the fast screening of influenza infections.
Secreted levels of HSP90? and overexpression of TCF12 have been associated with the enhancement of colorectal cancer (CRC) cell migration and invasion. In this study, we observed that CRC patients with tumor TCF12 overexpression exhibited both a higher rate of metastatic occurrence and a higher average serum HSP90? level compared with patients without TCF12 overexpression. Therefore, we studied the relationship between the actions of secreted HSP90? and TCF12. Like overexpressed TCF12, secreted HSP90? or recombinant HSP90? (rHSP90?) induced fibronectin expression and repressed E-cadherin, connexin-26, connexin-43, and gap junction levels in CRC cells. Consistently, rHSP90? stimulated invasive outgrowths of CRC cells from spherical structures during three-dimensional culture. rHSP90? also induced TCF12 expression in CRC cells. Its effects on CRC cell epithelial-mesenchymal transition, migration, and invasion were drastically prevented when TCF12 was knocked down. This suggests that TCF12 expression is required for secreted HSP90? to enhance CRC cell spreading. Through the cellular receptor CD91, rHSP90? facilitated the complex formation of CD91 with I?B kinases (IKKs) ? and ? and increased the levels of phosphorylated (active) IKK?/? and NF-?B. Use of an IKK?/? inhibitor or ectopic overexpression of dominant-negative I?B? efficiently repressed rHSP90?-induced TCF12 expression. Moreover, ?B motifs were recognized in the gene sequence of the TCF12 promoter, and a physical association between NF-?B and the TCF12 promoter was detected in rHSP90?-treated CRC cells. Together, these results suggest that the CD91/IKK/NF-?B signaling cascade is involved in secreted HSP90?-induced TCF12 expression, leading to E-cadherin down-regulation and enhanced CRC cell migration/invasion.
Cdc7-Dbf4 kinase (Dbf4-dependent kinase, DDK) is an essential factor of DNA replication and DNA damage response (DDR), which is associated with tumorigenesis. However, Cdc7 expression has never been associated to the outcome of oral squamous cell carcinoma (OSCC) patients, and the mechanism underlying cancer cell survival mediated by Cdc7 remains unclear. The Cdc7 protein expression of 105 OSCC tumor and 30 benign tissues was examined by immunohistochemistry assay. Overall survival rates of 80 OSCC patients were measured using Kaplan-Meier estimates and the log-rank tests. Cdc7 overexpression by adenovirus system was used to scrutinize the underlying mechanism contributed to cancer cell survival upon DDR. In silico analysis showed that increased Cdc7 is a common feature of cancer. Cdc7 overexpression was found in 96 of 105 (91.4%) studied cases of OSCC patients. Patients with higher Cdc7 expression, either categorized into two groups: Cdc7 high expression (2+ to 3+) versus Cdc7 low expression (0 to 1+) [hazard ratios (HR)=2.6; 95% confidence interval (CI)=1.28-5.43; P=0.0087] or four groups (0 to 3+) [HR=1.71; 95% CI=1.20-2.44; P=0.0032], exhibited a poorer outcome. Multivariate analysis showed that Cdc7 is an independent marker for survival prediction. Overexpressed Cdc7 inhibits genotoxin-induced apoptosis to increase the survival of cancer cells. In summary, Cdc7 expression, which is universally upregulated in cancer, is an independent prognostic marker of OSCC. Cdc7 inhibits genotoxin-induced apoptosis and increases survival in cancer cells upon DDR, suggesting that high expression of Cdc7 enhances the resistance to chemotherapy.
In previous research, we found ?-enolase to be inversely correlated with progression-free and overall survival in lung cancer patients and detected ?-enolase on the surface of lung cancer cells. Based on these findings, we hypothesized that surface ?-enolase has a significant role in cancer metastasis and tested this hypothesis in the current study. We found that ?-enolase was co-immunoprecipitated with urokinase-type plasminogen activator, urokinase-type plasminogen activator receptor, and plasminogen in lung cancer cells and interacted with these proteins in a cell-free dot blotting assay, which can be interrupted by ?-enolase-specific antibody. ?-Enolase in lung cancer cells co-localized with these proteins and was present at the site of pericellular degradation of extracellular matrix components. Treatment with antibody against ?-enolase in vitro suppressed cell-associated plasminogen and matrix metalloproteinase activation, collagen and gelatin degradation, and cell invasion. Examination of the effect of treatment with shRNA plasmids revealed that down regulation of ?-enolase decreases extracellular matrix degradation by and the invasion capacity of lung cancer cells. Adoptive transfer of ?-enolase-specific antibody to mice resulted in accumulation of antibody in subcutaneous tumor and inhibited the formation of tumor metastasis in lung and bone. This study demonstrated that surface ?-enolase promotes extracellular matrix degradation and invasion of cancer cells and that targeting surface ?-enolase is a promising approach to suppress tumor metastasis.
A correlation of TCF12 mRNA overexpression with colorectal cancer (CRC) metastasis was suggested by microarray data and validated by the survey of 120 patients. Thirty-three (27.5%) of the 120 patients showed tumor TCF12 mRNA overexpression and had a higher rate of metastatic occurrence (p = 0.020) and a poorer survival outcome (p = 0.014). Abundant TCF12 levels were also observed in human CRC cell lines such as SW620 and LoVo, but a relatively low level was detected in SW480 cells. Knockdown of TCF12 expression in SW620 and LoVo cells drastically reduced their activities of migration, invasion, and metastasis. Tight cell-cell contact and an increase in E-cadherin but a concomitant decrease in fibronectin were observed in TCF12-knockdown cells. Connexin 26, connexin 43, and gap-junction activity were also increased upon TCF12-knockdown. In contrast, ectopic TCF12 overexpression in SW480 cells facilitated fibronectin expression and cell migration and invasion activities but diminished cellular levels of E-cadherin, connexin 26, connexin 43, and gap junction. A physical association of TCF12 with the E-cadherin promoter was evidenced by chromatin immunoprecipitation assay. TCF12 was tightly correlated with cellular expression of Bmi1 and EZH2 and was co-immunoprecipitable with Bmi1 and EZH2, suggesting that TCF12 transcriptionally suppressed E-cadherin expression via polycomb group-repressive complexes. Clinically, TCF12 mRNA overexpression was also correlated with E-cadherin mRNA down-regulation in the tumor tissues of our 120 patients (p = 0.013). These studies suggested that TCF12 functioned as a transcriptional repressor of E-cadherin and its overexpression was significantly correlated with the occurrence of CRC metastasis.
ASC/PYCARD is a common adaptor for a diverse set of inflammasomes that activate caspase-1, most prominently the NLR-based inflammasome. Mounting evidence indicates that ASC and these NLRs also elicit non-overlapping functions, but the molecular basis for this difference is unclear. To address this, we performed microarray and network analysis of ASC shRNA knockdown cells. In pathogen-infected cells, an ASC-dependent interactome is centered on the mitogen-activated protein kinase (MAPK) ERK and on multiple chemokines. ASC did not affect the expression of MAPK but affected its phosphorylation by pathogens and Toll-like receptor agonists via suppression of the dual-specificity phosphatase, DUSP10/MKP5. Chemokine induction, DUSP function, and MAPK phosphorylation were independent of caspase-1 and IL-1?. MAPK activation by pathogen was abrogated in Asc(-/-) but not Nlrp3(-/-), Nlrc4(-/-), or Casp1(-/-) macrophages. These results demonstrate a function for ASC that is distinct from the inflammasome in modulating MAPK activity and chemokine expression and further identify DUSP10 as a novel ASC target.
The enzyme-linked immunosorbent assay (ELISA) is widely used in medical diagnostics. In order to reduce the diagnosis time and to lower the consumption of sample/reagents in an ELISA assay, a suction-type, automatic, pneumatically-driven microfluidic chip has been designed and fabricated in this study. The microfluidic chip integrates a multi-functional micro-transport/mixing unit, for transporting metering and mixing of samples and reagents in order to automatically perform the entire ELISA protocol. A new surface modification has been adopted which allows for a high processing capacity. The detection sensitivity for the dengue virus is found to be 10(1) PFU/ml, which is much better than a conventional ELISA assay (10(3) PFU/ml). The entire assay time is only 30 min, which is much faster than with 96-well microtiter plates (4 h). The consumed sample and reagent volume is only 12 ?l, which is less than a conventional assay (100 ?l). The development of this microfluidic chip may be promising for other immunosensing applications.
Positive correlation between caseload and outcome has previously been validated for several procedures and cancer treatments. However, there is no information linking caseload and outcome of nasopharyngeal carcinoma (NPC) treatment. We used nationwide population-based data to examine the association between physician case volume and survival rates of patients with NPC.
This study reports a new immunomagnetic bead-based microfluidic system for the rapid detection of influenza A virus infection by performing a simple two-step diagnostic process that includes a magnetic bead-based fluorescent immunoassay (FIA) and an end-point optical analysis. With the incorporation of monoclonal antibody (mAb)-conjugated immunomagnetic beads, target influenza A viral particles such as A/H(1)N(1) and A/H(3)N(2) can be specifically recognized and are bound onto the surface of the immunomagnetic beads from the specimen sample. This is followed by labeling the fluorescent signal onto the virus-bound magnetic complexes by specific developing mAb with R-phycoerythrin (PE). Finally, the optical intensity of the magnetic complexes can be analyzed immediately by the optical detection module. Significantly, the limit of detection (LOD) of this immunomagnetic bead-based microfluidic system for the detection of influenza A virus in a specimen sample is approximately 5×10(-4) hemagglutin units (HAU), which is 1024 times better than compared to conventional bench-top systems using flow cytometry. More importantly, the entire diagnostic protocol, from the purification of target viral particles to optical detection of the magnetic complexes, can be automatically completed within 15min in this immunomagnetic bead-based microfluidic system, which is only 8.5% of the time required when compared to a manual protocol. As a whole, this microfluidic system may provide a powerful platform for the rapid diagnosis of influenza A virus infection and may be extended for diagnosis of other types of infectious diseases with a high specificity and sensitivity.
High-fat diet (HFD) and inflammation are key contributors to insulin resistance and type 2 diabetes (T2D). Interleukin (IL)-1? plays a role in insulin resistance, yet how IL-1? is induced by the fatty acids in an HFD, and how this alters insulin signaling, is unclear. We show that the saturated fatty acid palmitate, but not unsaturated oleate, induces the activation of the NLRP3-ASC inflammasome, causing caspase-1, IL-1? and IL-18 production. This pathway involves mitochondrial reactive oxygen species and the AMP-activated protein kinase and unc-51-like kinase-1 (ULK1) autophagy signaling cascade. Inflammasome activation in hematopoietic cells impairs insulin signaling in several target tissues to reduce glucose tolerance and insulin sensitivity. Furthermore, IL-1? affects insulin sensitivity through tumor necrosis factor-independent and dependent pathways. These findings provide insights into the association of inflammation, diet and T2D.
Dendritic cell (DC)-based adoptive tumor immunotherapy approaches have shown promising results, but the incidence of tumor regression is low and there is an evident call for identifying culture conditions that produce DCs with a more potent Th1 potential. Routinely, DCs are differentiated in CO(2) incubators under atmospheric oxygen conditions (21% O(2)), which differ from physiological oxygen levels of only 3-5% in tissue, where most DCs reside. We investigated whether differentiation and maturation of DCs under physiological oxygen levels could produce more potent T-cell stimulatory DCs for use in adoptive immunotherapy. We found that immature DCs differentiated under physiological oxygen levels showed a small but significant reduction in their endocytic capacity. The different oxygen levels did not influence their stimuli-induced upregulation of cluster of differentiation 54 (CD54), CD40, CD83, CD86, C-C chemokine receptor type 7 (CCR7), C-X-C chemokine receptor type 4 (CXCR4) and human leukocyte antigen (HLA)-DR or the secretion of interleukin (IL)-6, tumor necrosis factor (TNF)-? and IL-10 in response to lipopolysaccharide (LPS) or a cytokine cocktail. However, DCs differentiated under physiological oxygen level secreted higher levels of IL-12(p70) after exposure to LPS or CD40 ligand. Immature DCs differentiated at physiological oxygen levels caused increased T-cell proliferation, but no differences were observed for mature DCs with regard to T-cell activation. In conclusion, we show that although DCs generated under atmospheric or physiological oxygen conditions are mostly similar in function and phenotype, DCs differentiated under physiological oxygen secrete larger amounts of IL-12(p70). This result could have implications for the use of ex vivo-generated DCs for clinical studies, since DCs differentiated at physiological oxygen could induce increased Th1 responses in vivo.
Francisella tularensis is a facultative intracellular pathogen and potential biothreat agent. Evasion of the immune response contributes to the extraordinary virulence of this organism although the mechanism is unclear. Whereas wild-type strains induced low levels of cytokines, an F. tularensis ripA deletion mutant (LVS?ripA) provoked significant release of IL-1?, IL-18, and TNF-? by resting macrophages. IL-1? and IL-18 secretion was dependent on inflammasome components pyrin-caspase recruitment domain/apoptotic speck-containing protein with a caspase recruitment domain and caspase-1, and the TLR/IL-1R signaling molecule MyD88 was required for inflammatory cytokine synthesis. Complementation of LVS?ripA with a plasmid encoding ripA restored immune evasion. Similar findings were observed in a human monocytic line. The presence of ripA nearly eliminated activation of MAPKs including ERK1/2, JNK, and p38, and pharmacologic inhibitors of these three MAPKs reduced cytokine induction by LVS?ripA. Animals infected with LVS?ripA mounted a stronger IL-1? and TNF-? response than that of mice infected with wild-type live vaccine strain. This analysis revealed novel immune evasive mechanisms of F. tularensis.
HCT-8 colon cancer cells secreted heat shock protein 90alpha (HSP90alpha) and had increased invasiveness upon serum starvation. The concentrated conditioned medium of serum-starved HCT-8 cells was able to stimulate the migration and invasion of non-serum-starved cells, which could be prevented by treatment with an anti-HSP90alpha antibody. Recombinant HSP90alpha (rHSP90alpha) also enhanced HCT-8 cell migration and invasion, suggesting a stimulatory role of secreted HSP90alpha in cancer malignancy. HSP90alpha binding to CD91alpha and Neu was evidenced by the proximity ligation assay, and rHSP90alpha-induced HCT-8 cell invasion could be suppressed by the addition of anti-CD91alpha or anti-Neu antibodies. Via CD91alpha and Neu, rHSP90alpha selectively induced integrin alpha(V) expression, and knockdown of integrin alpha(V) efficiently blocked rHSP90alpha-induced HCT-8 cell invasion. rHSP90alpha induced the activities of ERK, PI3K/Akt, and NF-kappaB p65, but only NF-kappaB activation was involved in HSP90alpha-induced integrin alpha(V) expression. Additionally, we investigated the serum levels of HSP90alpha and the expression status of tumor integrin alpha(V) mRNA in colorectal cancer patients. Serum HSP90alpha levels of colorectal cancer patients were significantly higher than those of normal volunteers (p < 0.001). Patients with higher serum HSP90alpha levels significantly exhibited elevated levels of integrin alpha(V) mRNA in tumor tissues as compared with adjacent non-tumor tissues (p < 0.001). Furthermore, tumor integrin alpha(V) overexpression was significantly correlated with TNM (Tumor, Node, Metastasis) staging (p = 0.001).
Oral squamous cell carcinoma (OSCC) is an aggressive tumor and its occurrence in Taiwan is closely related to chronic smoking, alcohol consumption, and especially to betel quid chewing. It became the fourth most common malignant tumor of Taiwanese men in 2006. Unfortunately, there are few biomarkers for diagnosis and treatment of this disease.
alpha-Chaconine, a naturally occurring steroidal glycoalkaloid in potato sprouts, was found to possess anti-carcinogenic properties, such as inhibiting proliferation, migration, invasion, and inducing apoptosis of tumor cells. However, the effect of alpha-chaconine on tumor angiogenesis remains unclear. In the present study, we examined the effect of alpha-chaconine on angiogenesis in vitro. Data demonstrated that alpha-chaconine inhibited proliferation of bovine aortic endothelial cells (BAECs) in a dose-dependent manner. When treated with non-toxic doses of alpha-chaconine, cell migration, invasion and tube formation were markedly suppressed. Furthermore, alpha-chaconine reduced the expression and activity of matrix metalloproteinase-2 (MMP-2), which is involved in angiogenesis. Our biochemical assays indicated that alpha-chaconine potently suppressed the phosphorylation of c-Jun N-terminal kinase (JNK), phosphatidylinositide-3 kinase (PI3K) and Akt, while it did not affect phosphorylation of extracellular signal regulating kinase (ERK) and p38. In addition, alpha-chaconine significantly increased the cytoplasmic level of inhibitors of kappaBalpha (IkappaBalpha) and decreased the nuclear level of nuclear factor kappa B (NF-kappaB), suggesting that alpha-chaconine could inhibit NF-kappaB activity. Furthermore, the treatment of inhibitors specific for JNK (SP600125), PI3K (LY294002) or NF-kappaB (pyrrolidine dithiocarbamate) to BAECs reduced tube formation. Taken together, the results suggested that alpha-chaconine inhibited migration, invasion and tube formation of BAECs by reducing MMP-2 activities, as well as JNK and PI3K/Akt signaling pathways and inhibition of NF-kappaB activity. These findings reveal a new therapeutic potential for alpha-chaconine on anti-angiogenic therapy.
Shortly after the cellular mechanism of RNA interference (RNAi) was first described, scientists began using this powerful technique to study gene function. This included designing better methods for the successful delivery of small interfering RNAs (siRNAs) and short hairpin RNAs (shRNAs) into mammalian cells. While the simplest method for RNAi is the cytosolic delivery of siRNA oligonucleotides, this technique is limited to cells capable of transfection and is primarily utilized during transient in vitro studies. The introduction of shRNA into mammalian cells through infection with viral vectors allows for stable integration of shRNA and long-term knockdown of the targeted gene; however, several challenges exist with the implementation of this technology. Here we describe some well-tested protocols which should increase the chances of successful design, delivery, and assessment of gene knockdown by shRNA. We provide suggestions for designing shRNA targets and controls, a protocol for sequencing through the secondary structure of the shRNA hairpin structure, and protocols for packaging and delivery of shRNA lentiviral particles. Using real-time PCR and functional assays we demonstrate the successful knockdown of ASC, an inflammatory adaptor molecule. These studies demonstrate the practicality of including two shRNAs with different efficacies of knockdown to provide an additional level of control and to verify dose dependency of functional effects. Along with the methods described here, as new techniques and algorithms are designed in the future, shRNA is likely to include further promising application and continue to be a critical component of gene discovery.
A recombinant putative acid phosphatase from Thermus thermophilus was expressed and purified from Escherichia coli. The recombinant phosphatase displayed activities in a broad range of temperature, from 40 to 90 degrees C, with optimal temperature at 70 degrees C. In addition, the recombinant enzyme had activities in a wide range of pH, from 3.6 to 9.1, with optimal pH at 6 in acetate buffer and with optimal pH at 6.5 in Hepes buffer. Furthermore, it showed significant thermal stability and still possessed 44% residual activity after 70 degrees C treatment for 15 min. Moreover, the recombinant phosphatase showed broad substrates specificities for monophosphate esters, p-nitrophenyl phosphate (pNPP) being the most preferred substrate, and it was able to resist inhibition by sodium tartrate. Additionally, the recombinant protein formed stable oligomer under partially denatured conditions and required calcium ions for enzymic activity.
Nanoparticles (NPs) are attractive carriers for vaccines. We have previously shown that a short peptide (Hp91) activates dendritic cells (DCs), which are critical for initiation of immune responses. In an effort to develop Hp91 as a vaccine adjuvant with NP carriers, we evaluated its activity when encapsulated in or conjugated to the surface of poly(d,l-lactic-co-glycolic) acid (PLGA) NPs. We found that Hp91, when encapsulated in or conjugated to the surface of PLGA-NPs, not only activates both human and mouse DCs, but is in fact more potent than free Hp91. Hp91 packaged within NPs was about fivefold more potent than the free peptide, and Hp91 conjugated to the surface of NPs was ?20-fold more potent than free Hp91. Because of their capacity to activate DCs, such NP-Hp91 systems are promising as delivery vehicles for subunit vaccines against infectious disease or cancer.
Current staging systems have limited ability to adjust optimal therapy in advanced nasopharyngeal carcinoma (NPC). This study aimed to delineate the correlation between tumor volume, treatment outcome and chemotherapy cycles in advanced NPC.
Bacterial infection elicits a range of beneficial as well as detrimental host inflammatory responses. Key among these responses are macrophage/monocyte necrosis, release of the proinflammatory factor high-mobility group box 1 protein (HMGB1), and induction of the cytokine IL-1. Although the control of IL-1beta has been well studied, processes that control macrophage cell death and HMGB1 release in animals are poorly understood. This study uses Klebsiella pneumonia as a model organism because it elicits all three responses in vivo. The regulation of these responses is studied in the context of the inflammasome components NLRP3 and ASC, which are important for caspase-1 activation and IL-1beta release. Using a pulmonary infection model that reflects human infection, we show that K. pneumonia-induced mouse macrophage necrosis, HMGB1, and IL-1beta release are dependent on NLRP3 and ASC. K. pneumoniae infection of mice lacking Nlrp3 results in decreased lung inflammation and reduced survival relative to control, indicating the overall protective role of this gene. Macrophage/monocyte necrosis and HMGB1 release are controlled independently of caspase-1, suggesting that the former two responses are separable from inflammasome-associated functions. These results provide critical in vivo validation that the physiologic role of NLRP3 and ASC is not limited to inflammasome formation.
Neisseria gonorrhoeae is a common sexually transmitted pathogen that significantly impacts female fertility, neonatal health, and transmission of HIV worldwide. N. gonorrhoeae usually causes localized inflammation of the urethra and cervix by inducing production of IL-1beta and other inflammatory cytokines. Several NLR (nucleotide-binding domain, leucine-rich repeat) proteins are implicated in the formation of pro-IL-1beta-processing complexes called inflammasomes in response to pathogens. We demonstrate that NLRP3 (cryopyrin, NALP3) is the primary NLR required for IL-1beta/IL-18 secretion in response to N. gonorrhoeae in monocytes. We also show that N. gonorrhoeae infection promotes NLRP3-dependent monocytic cell death via pyronecrosis, a recently described pathway with morphological features of necrosis, including release of the strong inflammatory mediator HMBG1. Additionally, N. gonorrhoeae activates the cysteine protease cathepsin B as measured by the breakdown of a cathepsin B substrate. Inhibition of cathepsin B shows that this protease is an apical controlling step in the downstream activities of NLRP3 including IL-1beta production, pyronecrosis, and HMGB1 release. Nonpathogenic Neisseria strains (Neisseria cinerea and Neisseria flavescens) do not activate NLRP3 as robustly as N. gonorrhoeae. Conditioned medium from N. gonorrhoeae contains factors capable of initiating the NLRP3-mediated signaling events. Isolated N. gonorrhoeae lipooligosaccharide, a known virulence factor from this bacterium that is elaborated from the bacterium in the form of outer membrane blebs, activates both NLRP3-induced IL-1beta secretion and pyronecrosis. Our findings indicate that activation of NLRP3-mediated inflammatory response pathways is an important venue associated with host response and pathogenesis of N. gonorrhoeae.
Nasal-ala pressure sores induced by nasotracheal intubation are common complications of oral and maxillofacial surgery, but are easily ignored. To determine whether such sores could be prevented, we studied the effects of a combination of cushioning material in an animal model, and then analyzed the efficacy of this combination clinically.
Periodontal disease is a chronic inflammatory disorder that leads to the destruction of tooth-supporting tissue and affects 10-20 million people in the U.S. alone. The oral pathogen Porphyromonas gingivalis causes inflammatory host response leading to periodontal and other secondary inflammatory diseases. To identify molecular components that control host response to P. gingivalis in humans, roles for the NLR (NBD-LRR) protein, NLRP3 (cryopyrin, NALP3), and its adaptor apoptotic speck protein containing a C-terminal caspase recruitment domain (ASC) were studied. P. gingivalis strain A7436 induces cell death in THP1 monocytic cells and in human primary peripheral blood macrophages. This process is ASC and NLRP3 dependent and can be replicated by P. gingivalis LPS and Escherichia coli. P. gingivalis-induced cell death is caspase and IL-1 independent and exhibits morphological features consistent with necrosis including loss of membrane integrity and release of cellular content. Intriguingly, P. gingivalis-induced cell death is accompanied by the formation of ASC aggregation specks, a process not previously described during microbial infection. ASC specks are observed in P. gingivalis-infected primary human mononuclear cells and are dependent on NLRP3. This work shows that P. gingivalis causes ASC- and NLRP3-dependent necrosis, accompanied by ASC speck formation.
In resected buccal cancer patients, an unexpected close surgical margin has been observed to correlate with poor clinical outcomes. However, close surgical margin alone does not independently guide post-operative therapies, revealing a clinical debate. Hence, the present study intended to explore epigenetic-based bio-predictors for further stratifying this debating patient population.
The interleukin (IL)-1?-processing inflammasome has recently been identified as a target for pathogenic evasion of the inflammatory response by a number of bacteria and viruses. We postulated that the periodontal pathogen, Porphyromonas gingivalis may suppress the inflammasome as a mechanism for its low immunogenicity and pathogenic synergy with other, more highly immunogenic periodontal bacteria. Our results show that P. gingivalis lacks signaling capability for the activation of the inflammasome in mouse macrophages. Furthermore, P. gingivalis can suppress inflammasome activation by another periodontal bacterium, Fusobacterium nucleatum. This repression affects IL-1? processing, as well as other inflammasome-mediated processes, including IL-18 processing and cell death, in both human and mouse macrophages. F. nucleatum activates IL-1? processing through the Nlrp3 inflammasome; however, P. gingivalis repression is not mediated through reduced levels of inflammasome components. P. gingivalis can repress Nlrp3 inflammasome activation by Escherichia coli, and by danger-associated molecular patterns and pattern-associated molecular patterns that mediate activation through endocytosis. However, P. gingivalis does not suppress Nlrp3 inflammasome activation by ATP or nigericin. This suggests that P. gingivalis may preferentially suppress endocytic pathways toward inflammasome activation. To directly test whether P. gingivalis infection affects endocytosis, we assessed the uptake of fluorescent particles in the presence or absence of P. gingivalis. Our results show that P. gingivalis limits both the number of cells taking up beads and the number of beads taken up for bead-positive cells. These results provide a novel mechanism of pathogen-mediated inflammasome inhibition through the suppression of endocytosis.
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