Infectious Agent and Immune Response Characteristics of Chronic Enterocolitis in Captive Rhesus Macaques

Infection and Immunity. Jul, 2003  |  Pubmed ID: 12819098

Chronic enterocolitis is the leading cause of morbidity in colonies of captive rhesus macaques (Macaca mulatta). This study's aim was to identify the common enteric pathogens frequently associated with chronic enterocolitis in normal, immunocompetent rhesus monkeys and to elucidate the influence of this clinical syndrome on the host immune system. We analyzed the fecal specimens from 100 rhesus macaques with or without clinical symptoms of chronic diarrhea. Retrospective analysis revealed an increased incidence of Campylobacter spp. (Campylobacter coli and Campylobacter jejuni), Shigella flexneri, Yersinia enterocolitica, adenovirus, and Strongyloides fulleborni in samples collected from animals with chronic diarrhea (P < 0.05). The presence of additional enteric pathogens, such as Escherichia coli, carrying the eaeA intimin or Stx2c Shiga toxin virulence genes, Balantidium coli, Giardia lamblia, Enterocytozoon bieneusi, and Trichuris trichiura was found in all animals regardless of whether diarrhea was present. In addition, the upregulation of interleukin-1 alpha (IL-1 alpha), IL-3, and tumor necrosis factor alpha cytokine genes, accompanied by an increased presence of activated (CD4(+) CD69(+)) T lymphocytes was found in gut-associated lymphoid tissues collected from animals with chronic enterocolitis and diarrhea in comparison with clinically healthy controls (P < 0.05). These data indicate that chronic enterocolitis and diarrhea are associated, in part, with a variety of enteric pathogens and highlight the importance of defining the microbiological status of nonhuman primates used for infectious disease studies. The data also suggest that chronic colitis in rhesus macaques may have potential as a model of inflammatory bowel disease in humans.

Identification of Proteases Employed by Dendritic Cells in the Processing of Protein Purified Derivative (PPD)

Journal of Immune Based Therapies and Vaccines. Aug, 2004  |  Pubmed ID: 15287985

Dendritic cells (DC) are known to present exogenous protein Ag effectively to T cells. In this study we sought to identify the proteases that DC employ during antigen processing. The murine epidermal-derived DC line Xs52, when pulsed with PPD, optimally activated the PPD-reactive Th1 clone LNC.2F1 as well as the Th2 clone LNC.4k1, and this activation was completely blocked by chloroquine pretreatment. These results validate the capacity of XS52 DC to digest PPD into immunogenic peptides inducing antigen specific T cell immune responses. XS52 DC, as well as splenic DC and DCs derived from bone marrow degraded standard substrates for cathepsins B, C, D/E, H, J, and L, tryptase, and chymases, indicating that DC express a variety of protease activities. Treatment of XS52 DC with pepstatin A, an inhibitor of aspartic acid proteases, completely abrogated their capacity to present native PPD, but not trypsin-digested PPD fragments to Th1 and Th2 cell clones. Pepstatin A also inhibited cathepsin D/E activity selectively among the XS52 DC-associated protease activities. On the other hand, inhibitors of serine proteases (dichloroisocoumarin, DCI) or of cystein proteases (E-64) did not impair XS52 DC presentation of PPD, nor did they inhibit cathepsin D/E activity. Finally, all tested DC populations (XS52 DC, splenic DC, and bone marrow-derived DC) constitutively expressed cathepsin D mRNA. These results suggest that DC primarily employ cathepsin D (and perhaps E) to digest PPD into antigenic peptides.

Development of a Rotavirus-shedding Model in Rhesus Macaques, Using a Homologous Wild-type Rotavirus of a New P Genotype

Journal of Virology. Jan, 2005  |  Pubmed ID: 15613323

Although there are several reports on rotavirus inoculation of nonhuman primates, no reliable model exists. Therefore, this study was designed to develop a rhesus macaque model for rotavirus studies. The goals were to obtain a wild-type macaque rotavirus and evaluate it as a challenge virus for model studies. Once rotavirus was shown to be endemic within the macaque colony at the Tulane National Primate Research Center, stool specimens were collected from juvenile animals (2.6 to 5.9 months of age) without evidence of previous rotavirus infection and examined for rotavirus antigen. Six of 10 animals shed rotavirus during the 10-week collection period, and the electropherotypes of all isolates were identical to each other but distinct from those of prototype simian rotaviruses. These viruses were characterized as serotype G3 and subgroup 1, properties typical of many animal rotaviruses, including simian strains. Nucleotide sequence analysis of the VP4 gene was performed with a culture-grown isolate from the stool of one animal, designated the TUCH strain. Based on both genotypic and phylogenetic comparisons between TUCH VP4 and cognate proteins of representatives of the reported 22 P genotypes, the TUCH virus belongs to a new genotype, P[23]. A pool of wild-type TUCH was prepared and intragastrically administered to eight cesarean section-derived, specific-pathogen-free macaques 14 to 42 days of age. All animals were kept in a biocontainment level 2 facility. Although no diarrhea was observed and the animals remained clinically normal, all animals shed large quantities of rotavirus antigen in their feces after inoculation, which resolved by the end of the 14-day observation period. Therefore, TUCH infection of macaques provides a useful nonhuman primate model for studies on rotavirus protection.

Visualizing Cytokine-secreting Cells in Situ in the Rhesus Macaque Model of Chronic Gut Inflammation

Clinical and Diagnostic Laboratory Immunology. Jan, 2005  |  Pubmed ID: 15643006

Cytokine-producing cells in gut-associated lymphoid tissues of rhesus macaques with chronic enterocolitis were studied. The confocal microscopy technique that we developed enables simultaneous in situ visualization of multiple extra- and/or intracellular antigens at a resolution higher than that allowed by light or epifluorescence microscopy. The presence of interleukin-6 (IL-6)-, tumor necrosis factor alpha (TNF-alpha)-, and IL-1-alpha-producing cells was focally intense in the colon lamina propria of the affected animals. The IL-1-alpha-producing cells were T lymphocytes (CD3+), while the TNF-alpha-producing cells were both macrophages (CD68+/HAM56+/LN5+) and T lymphocytes (CD3+). The IL-6-producing cells within the colon consisted of T lymphocytes and macrophages. The amount of IL-6-producing cells seen in macaques with enterocolitis was significantly higher (P<0.001) than that seen in the healthy control animal, while TNF-alpha- and IL-1-alpha-producing cells were seen only in macaques with enterocolitis. Most of the T lymphocytes that produced cytokines were detected in the lamina propria, while the macrophages were most prominent in highly inflamed regions of the lamina propria. Taken together, our findings indicate that there might be immunological similarity between chronic enterocolitis of rhesus macaques and humans, suggesting the potential use of the nonhuman primate model for the validation of novel therapies.

Characterization of Cytolethal Distending Toxin of Campylobacter Species Isolated from Captive Macaque Monkeys

Journal of Clinical Microbiology. Feb, 2005  |  Pubmed ID: 15695658

An association between certain Campylobacter species and enterocolitis in humans and nonhuman primates is well established, but the association between cytolethal distending toxin and disease is incompletely understood. The purpose of the present study was to examine Campylobacter species isolated from captive conventionally raised macaque monkeys for the presence of the cdtB gene and for cytolethal distending toxin activity. The identity of each isolate was confirmed on the basis of phenotypic and genotypic analyses. The presence of cytolethal distending toxin was confirmed on the basis of characteristic morphological changes in HeLa cells incubated with filter-sterilized whole-cell lysates of reference and monkey Campylobacter isolates and examinations by light microscopy, confocal microscopy, and flow cytometry. Although cdtB gene sequences were found in both Campylobacter jejuni and Campylobacter coli, the production of cytolethal distending toxin correlated positively (P < 0.0001) only with C. jejuni. We concluded that cytolethal distending toxin activity is a characteristic of C. jejuni. Our C. jejuni cdtB gene-specific PCR assay might be of assistance for differentiating toxigenic C. jejuni from C. coli in clinical laboratories.

Chronic Diarrhea and AIDS: Insights into Studies with Non-human Primates

Current HIV Research. Jul, 2005  |  Pubmed ID: 16022653

Diarrhea is the pathophysiological reaction of host's gastrointestinal tract to a variety of external stimuli. Classified as a clinical syndrome, diarrhea is the leading cause of mortality and morbidity worldwide. Clinical manifestations can occur in two major forms: A) acute, which usually resolves in less than three weeks and B) chronic, which can last for months. Because of its impact on the host immune system, acquired immune deficiency syndrome (AIDS) is currently the major cause of chronic diarrhea in many parts of the world. It is estimated that up to 90% of HIV-infected individuals with symptoms of AIDS exhibit clinical diarrhea [9, 74, 55]. In SIV-infected rhesus macaques, intense infiltration of intestinal lamina propria with virus-containing lymphocytes and macrophages can be found within days after experimental virus inoculation [25, 57]. In addition to acute enteropathy syndrome, viral infection ultimately leads to other alterations of the gastrointestinal tract including persistent and/or chronic diarrhea, a condition similar to untreated AIDS of human patients. In this short review, the chronic diarrhea is presented from the perspective of the non-human primate or simian model of AIDS (SAIDS), and its most common opportunistic and pathogenic co-infections.

Evaluation of Rotavirus DsRNA Load in Specimens and Body Fluids from Experimentally Infected Juvenile Macaques by Real-time PCR

Virology. Oct, 2005  |  Pubmed ID: 16095646

We recently established a non-human primate model of rotavirus infection that is characterized by consistent and high levels of virus antigen shedding in stools. Here, we report that starting from post challenge day (PCD) 2, 6 x 10(3) to 1.5 x 10(6) copies of rotavirus double-stranded RNA per nanogram of total RNA were detected by real-time PCR in MA104 cells that were 48 h pre-incubated with filtered stool suspensions of three experimentally infected juvenile macaques. The peak of virus load was detected at PCD 4-5, followed by decreased load at PCD 6-11, and very low levels at PCD 12. Such a pattern corresponded to virus shedding in stools as reported recently based on enzyme-linked immunosorbent assay (ELISA) results. In addition, plasma and cerebrospinal fluids (CSF) from six infected animals were tested for the presence of rotavirus. Rotavirus extraintestinal escape was revealed in three out of six animals by a combination of real-time and nested PCR. However, very low quantities of detected viral RNA (approximately 20 copies/ng of total RNA) were not suggestive of viremia. Thus, the rhesus model of rotavirus infection can be exploited further in studies with vaccine candidates designed to prevent or abrogate rotavirus infection.

Summary of the Animal Homologue Section of HLDA8

Cellular Immunology. Jul-Aug, 2005  |  Pubmed ID: 16198325

Development of reagents against leukocyte differentiation antigens in veterinary immunology is slower compared to humans and mice. Cross-reactivity studies with monoclonal antibodies (mAb) generated against human molecules represent an excellent approach for the detection of new reagents for the minor characterised species. Three hundred seventy-seven commercially available mAb from different companies were tested for their reactivity with cells from 17 species--including non-human primates, ruminants, swine, horse, carnivores, rabbit, guinea pig, chicken and fish. In a first round of testing by flow cytometry (FCM) 182 mAb showed reactivity with atleast one of the species described above. Most of the cross-reactivity was found against non-human primate leukocytes, but also species in evolutionarily more distant from humans showed in some cases a clear staining pattern in flow cytometry (FCM). In a second round these FCM-results were confirmed by molecular analyses, by immunoprecipitation studies and analyses on transfectants. Interesting was the broad species-overlapping reactivity of mAb directed against CD9 (11 out of 17 species), CD11a (11/17), CD14 (11/17), CD18 (13/17), CD21 (7/17), CD29 (10/17), CD44 (13/17), CD45 (9/17), CD47 (10/17), and CD49d (13/17), CD61 (6/17), CD86 (7/17), CD91 (5/17), and CD172a (10/17), indicating evolutionary highly conserved epitopes on these surface molecules. Our results suggest the suitability of crossreactive mAb for the animal model studies. Moreover, these findings contribute to our understanding of the evolution of the immune system.

Loss of Grants Hurts the Vulnerable

Science (New York, N.Y.). Jan, 2006  |  Pubmed ID: 16410507

Single Epitope Mucosal Vaccine Delivered Via Immuno-stimulating Complexes Induces Low Level of Immunity Against Simian-HIV

Vaccine. Nov, 2006  |  Pubmed ID: 17050045

The difficulty in developing an effective vaccine to contain the HIV/AIDS epidemic coupled with the fact that primary HIV-1 infection typically occurs via mucosal sites has increased emphasis on vaccine approaches that protect at mucosal surfaces. In this study we employed HIV and simian-HIV (SHIV)-derived T helper (Th) and cytotoxic T lymphocyte (CTL) single epitopes incorporated into immuno-stimulating complexes (ISCOM) as a candidate immunogens. Immunized rhesus macaques (Macaca mulatta) were challenged with CCR5-tropic SHIV(SF162p4). On the day of challenge, low levels of virus-neutralizing antibodies (Ab) and CTLs were detected in ISCOM-immunized macaques. Greater than 10(5) viral RNA copies per ml of plasma in 2/5 immunized and 3/4 control macaques were detected within 3 weeks post-challenge. Depletion of CD4+ T cells from gut-associated lymphoid tissues (GALT) was observed by post-challenge day (PCD) 14 in all macaques regardless immunization. Nonetheless, lower viral loads and relatively better preservation of peripheral CD4+ T cells following the SHIV infection was observed in ISCOM-immunized macaques. We predict that if coadministered with additional epitopes and/or more efficacious mucosal delivery system or route, HIV/SIV-derived peptide vaccines may have potential to elicit heterologous protection.

Identification of Anti-human CD Antibodies Reactive with Rhesus Macaque Peripheral Blood Cells

Veterinary Immunology and Immunopathology. Sep, 2007  |  Pubmed ID: 17681612

Three hundred and seventy seven commercially available monoclonal antibodies (mAb) were tested for their cross-reactivity with rhesus macaque (Macaca mulatta) peripheral blood cells. These antibodies were collected by the animal homologue section of the HLDA8 Workshop in order to assign their potential applicability for in vitro assays. Reactivity of each mAb with lymphocyte, monocyte and granulocyte populations obtained from peripheral blood of adult rhesus macaques was evaluated. Single-colour flow cytometry and indirect labeling method was used in first-round screening. Based on their reactivity with rhesus macaque cells 57 positive mAb were selected for second-round testing. Multi-colour flow cytometry and combinations of direct and indirect labeling was used to compare the reactivity of the respective mAb. In addition, reference reagents known to react with rhesus macaque CD3, CD20 and CD56 were used to further characterization of the reactivity of the selected 57 mAb on peripheral blood cells.

A Decline in CCL3-5 Chemokine Gene Expression During Primary Simian-human Immunodeficiency Virus Infection

PloS One. 2007  |  Pubmed ID: 17684570

The CC-chemokines CCL3, CCL4 and CCL5 have been found to block the entry of CCR5-tropic HIV into host cells and to suppress the viral replication in vitro, but the in vivo role of endogenous CC-chemokines in HIV-1 infection is still incompletely understood.

A Non-human Primate Model for Gluten Sensitivity

PloS One. 2008  |  Pubmed ID: 18286171

Gluten sensitivity is widespread among humans. For example, in celiac disease patients, an inflammatory response to dietary gluten leads to enteropathy, malabsorption, circulating antibodies against gluten and transglutaminase 2, and clinical symptoms such as diarrhea. There is a growing need in fundamental and translational research for animal models that exhibit aspects of human gluten sensitivity.

Transepithelial Transport and Enzymatic Detoxification of Gluten in Gluten-sensitive Rhesus Macaques

PloS One. 2008  |  Pubmed ID: 18365012

In a previous report, we characterized a condition of gluten sensitivity in juvenile rhesus macaques that is similar in many respects to the human condition of gluten sensitivity, celiac disease. This animal model of gluten sensitivity may therefore be useful toward studying both the pathogenesis and the treatment of celiac disease. Here, we perform two pilot experiments to demonstrate the potential utility of this model for studying intestinal permeability toward an immunotoxic gluten peptide and pharmacological detoxification of gluten in vivo by an oral enzyme drug candidate.

Characterization of a Rhesus Monkey Calicivirus Representing a New Genus of Caliciviridae

Journal of Virology. Jun, 2008  |  Pubmed ID: 18385231

In this study, we report the characterization of a novel calicivirus (CV), the Tulane virus (TV), which was isolated from stool samples of captive juvenile rhesus macaques (Macaca mulatta) of the Tulane National Primate Research Center. The complete genome of TV contains 6,714 nucleotides plus a poly(A) tail and is organized into three open reading frames (ORFs) that encode the nonstructural (NS) polyprotein (ORF1); the capsid protein (ORF2), with an estimated molecular mass of 57.9 kDa; and a possible minor structural protein (ORF3), with an isoelectric point (pI) of 10.0 and a calculated molecular mass of 22.8 kDa. The NS polyprotein revealed all typical CV amino acid motifs, including GXXGXGKT (NTPase), EYXEX (Vpg), GDCG (protease), and GLPSG and YGDD (polymerase). Phylogenetic trees constructed for the NS polyprotein, NTPase, protease, polymerase, and capsid protein sequences consistently placed the TV on a branch rooted with Norovirus, but with distances equal to those between other genera. The TV can be cultured in a monkey kidney cell line (LLC-MK2) with the appearance of typical cytopathic effect. TV exhibits a typical CV morphology, with a diameter of 36 nm, and has a buoyant density of 1.37 g/ml. According to these physicochemical and genetic characteristics, TV represents a new CV genus for which we propose the name "Recovirus" (rhesus enteric CV). Although the pathogenicity of TV in rhesus macaques remains to be elucidated, the likelihood of TV causing intestinal infection and the availability of a tissue culture system make this virus a valuable surrogate for human CVs.

Recovery of Infectious Virus by Transfection of in Vitro-generated RNA from Tulane Calicivirus CDNA

Journal of Virology. Nov, 2008  |  Pubmed ID: 18787011

Tulane virus (TV) is a newly reported calicivirus that was isolated from stool samples of captive rhesus macaques from the Tulane National Primate Research Center (TNPRC). The virus has been cultivated successfully in LLC-MK2 rhesus monkey kidney cells. Its complete genomic sequence suggests that TV represents a new genus and is evolutionarily more closely related to Norovirus than to any other genus of Caliciviridae. In this study, we demonstrated that RNA transcripts made in vitro from the full-length genomic cDNA of TV were infectious upon transfection into permissive LLC-MK2 cells. The recombinant virus exhibited plaque morphologies and growth kinetics similar to those of the wild-type virus in this cell line. Capping was required for TV RNA infectivity. Although a subgenomic RNA has been detected in TV-transfected cells, a separate subgenomic RNA transcript was not required for the initial transfection to establish the replication. Transfection of truncated RNA lacking open reading frame 2 (ORF2) and ORF3 or TV-norovirus chimeric RNA resulted in abortive replication without the production of infectious progeny viruses, indicating that both ORFs are essential for the replication of TV. A heterologous insertion at the 5' end of the genome also hampered viral replication, suggesting that an authentic 5' end of the genome is critical for replication. The availability of the complete genomic sequence and the reverse genetics system described herein make TV a valuable model for studying calicivirus pathogenesis and replication.

Identification of Rotavirus VP6-Specific CD4+ T Cell Epitopes in a G1P[8] Human Rotavirus-Infected Rhesus Macaque

Virology : Research and Treatment. Mar, 2008  |  Pubmed ID: 20401320

A non-human primate model was used to evaluate its potential for identification of rotavirus viral protein 6 (VP6) CD4+ T cell epitopes. Four juvenile rhesus macaques were inoculated with a mixed inoculum (G1P[8] and G9P[8]) of human rotaviruses. Infection accompanied by G1P[8] shedding was achieved in the two macaques that had no rotavirus immunoglobulin A (IgA) in plasma. To measure the interferon gamma (IFN-γ) and tumor necrosis factor (TNF) anti-viral cytokines produced by peripheral CD4+ cells that recognize VP6 epitopes, whole blood cells from one infected macaque were stimulated in vitro with VP6 peptides. Stimulation with peptide pools derived from the simian rotavirus VP6(161-395) region revealed reactivity of CD4+ T cells with the VP6(281-331) domain. A VP6(301-315) region was identified as the epitope responsible for IFN-γ production while a broader VP6(293-327) domain was linked to TNF production. These results suggest that human rotavirus-infected macaques can be used for identification of additional epitopes and domains to address specific questions related to the development of pediatric vaccines.

Noninflammatory Gluten Peptide Analogs As Biomarkers for Celiac Sprue

Chemistry & Biology. Aug, 2009  |  Pubmed ID: 19716477

New tools are needed for managing celiac sprue, a lifelong immune disease of the small intestine. Ongoing drug trials are also prompting a search for noninvasive biomarkers of gluten-induced intestinal change. We have synthesized and characterized noninflammatory gluten peptide analogs in which key Gln residues are replaced by Asn or His. Like their proinflammatory counterparts, these biomarkers are resistant to gastrointestinal proteases, susceptible to glutenases, and permeable across enterocyte barriers. Unlike gluten peptides, however, they are not appreciably recognized by transglutaminase, HLA-DQ2, or disease-specific T cells. In vitro and animal studies show that the biomarkers can detect intestinal permeability changes as well as glutenase-catalyzed gastric detoxification of gluten. Accordingly, controlled clinical studies are warranted to evaluate the use of these peptides as probes for abnormal intestinal permeability in celiac patients and for glutenase efficacy in clinical trials and practice.

Detection of Norovirus-, Sapovirus- and Rhesus Enteric Calicivirus-specific Antibodies in Captive Juvenile Macaques

The Journal of General Virology. Mar, 2010  |  Pubmed ID: 19889933

The objective of this study was to determine the prevalence of anti-norovirus (NoV), -sapovirus (SaV) and -Tulane virus (TV) antibodies in rhesus macaques of the Tulane National Primate Research Center and to evaluate the antigenic relationship between these viruses. A high prevalence of NoV-binding (51-61 %) and SaV-binding (50-56 %) antibodies and TV-neutralizing (69 %) antibodies were detected. Serum samples obtained during a human NoV outbreak and a multivalent anti-NoV hyperimmune serum were not able to neutralize TV infectivity. Conversely, low levels of cross-reactivity between the prototype TV and NoVs, but not between the TV and SaVs were detected by ELISA. These data indicate the preservation of some cross-reactive B-cell epitopes between the rhesus and human caliciviruses (CVs). The high prevalence of human and rhesus CV-specific serum antibodies suggests the frequent exposure of colony macaques to enteric CVs including the possibility of CV transmission between human and non-human primate hosts.

Simian Rotaviruses Possess Divergent Gene Constellations That Originated from Interspecies Transmission and Reassortment

Journal of Virology. Feb, 2010  |  Pubmed ID: 19939934

Although few simian rotaviruses (RVs) have been isolated, such strains have been important for basic research and vaccine development. To explore the origins of simian RVs, the complete genome sequences of strains PTRV (G8P[1]), RRV (G3P[3]), and TUCH (G3P[24]) were determined. These data allowed the genotype constellations of each virus to be determined and the phylogenetic relationships of the simian strains with each other and with nonsimian RVs to be elucidated. The results indicate that PTRV was likely transmitted from a bovine or other ruminant into pig-tailed macaques (its host of origin), since its genes have genotypes and encode outer-capsid proteins similar to those of bovine RVs. In contrast, most of the genes of rhesus-macaque strains, RRV and TUCH, have genotypes more typical of canine-feline RVs. However, the sequences of the canine and/or feline (canine/feline)-like genes of RRV and TUCH are only distantly related to those of modern canine/feline RVs, indicating that any potential transmission of a progenitor of these viruses from a canine/feline host to a simian host was not recent. The remaining genes of RRV and TUCH appear to have originated through reassortment with bovine, human, or other RV strains. Finally, comparison of PTRV, RRV, and TUCH genes with those of the vervet-monkey RV SA11-H96 (G3P[2]) indicates that SA11-H96 shares little genetic similarity to other simian strains and likely has evolved independently. Collectively, our data indicate that simian RVs are of diverse ancestry with genome constellations that originated largely by interspecies transmission and reassortment with nonhuman animal RVs.

Visualization of Transepithelial Passage of the Immunogenic 33-residue Peptide from Alpha-2 Gliadin in Gluten-sensitive Macaques

PloS One. 2010  |  Pubmed ID: 20419103

Based on clinical, histopathological and serological similarities to human celiac disease (CD), we recently established the rhesus macaque model of gluten sensitivity. In this study, we further characterized this condition based on presence of anti-tissue transglutaminase 2 (TG2) antibodies, increased intestinal permeability and transepithelial transport of a proteolytically resistant, immunotoxic, 33-residue peptide from alpha(2)-gliadin in the distal duodenum of gluten-sensitive macaques.

Genetic Diversity and Histo-blood Group Antigen Interactions of Rhesus Enteric Caliciviruses

Journal of Virology. Sep, 2010  |  Pubmed ID: 20554772

Recently, we reported the discovery and characterization of Tulane virus (TV), a novel rhesus calicivirus (CV) (T. Farkas, K. Sestak, C. Wei, and X. Jiang, J. Virol. 82:5408-5416, 2008). TV grows well in tissue culture, and it represents a new genus within Caliciviridae, with the proposed name of Recovirus. We also reported a high prevalence of CV antibodies in macaques of the Tulane National Primate Research Center (TNPRC) colony, including anti-norovirus (NoV), anti-sapovirus (SaV), and anti-TV (T. Farkas, J. Dufour, X. Jiang, and K. Sestak, J. Gen. Virol. 91:734-738, 2010). To broaden our knowledge about CV infections in captive nonhuman primates (NHP), 500 rhesus macaque stool samples collected from breeding colony TNPRC macaques were tested for CVs. Fifty-seven (11%) samples contained recovirus isolates. In addition, one NoV was detected. Phylogenetic analysis classified the recovirus isolates into two genogroups and at least four genetic types. The rhesus NoV isolate was closely related to GII human NoVs. TV-neutralizing antibodies were detected in 88% of serum samples obtained from primate caretakers. Binding and plaque reduction assays revealed the involvement of type A and B histo-blood group antigens (HBGA) in TV infection. Taken together, these findings indicate the zoonotic potential of primate CVs. The discovery of a genetically diverse and prevalent group of primate CVs and remarkable similarities between rhesus enteric CVs and human NoVs opens new possibilities for research involving in vitro and in vivo models of human NoV gastroenteritis.

Improved Xenobiotic Metabolism and Reduced Susceptibility to Cancer in Gluten-sensitive Macaques Upon Introduction of a Gluten-free Diet

PloS One. 2011  |  Pubmed ID: 21533263

A non-human primate (NHP) model of gluten sensitivity was employed to study the gene perturbations associated with dietary gluten changes in small intestinal tissues from gluten-sensitive rhesus macaques (Macaca mulatta).

The Rhesus Rotavirus Gene Encoding VP4 is a Major Determinant in the Pathogenesis of Biliary Atresia in Newborn Mice

Journal of Virology. Sep, 2011  |  Pubmed ID: 21697466

Biliary atresia (BA) is a devastating disease of childhood for which increasing evidence supports a viral component in pathogenesis. The murine model of BA is induced by perinatal infection with rhesus rotavirus (RRV) but not with other strains of rotavirus, such as TUCH. To determine which RRV gene segment(s) is responsible for pathogenesis, we used the RRV and TUCH strains to generate a complete set of single-gene reassortants. Eleven single-gene "loss-of-function" reassortants in which a TUCH gene replaced its RRV equivalent and 11 single-gene "gain-of-function" reassortants in which an RRV gene replaced its TUCH equivalent were generated. Newborn BALB/c mice were inoculated with the reassortants and were monitored for biliary obstruction and mortality. In vitro, the ability to bind to and replicate within cholangiocytes was analyzed. Infection of mice with the "loss-of-function" reassortant R(T(VP4)), where gene 4 from TUCH was placed on an RRV background, eliminated the ability of RRV to cause murine BA. In a reciprocal fashion, the "gain-of-function" reassortant T(R(VP4)) resulted in murine BA with 88% mortality. Compared with those for RRV, R(T(VP4)) binding and titers in cholangiocytes were significantly attenuated, while T(R(VP4)) binding and titers were significantly increased over those for TUCH. Reassortants R(T(VP3)) and T(R(VP3)) induced an intermediate phenotype. RRV gene segment 4 plays a significant role in governing tropism for the cholangiocyte and the ability to induce murine BA. Gene segment 3 did not affect RRV infectivity in vitro but altered its in vivo effect.