Defining T-Cell-Mediated Immune Responses in Rotavirus-Infected Juvenile Rhesus Macaques

Abstract

The appearance of virus-specific CD4؉ and/or CD8 ؉ T lymphocytes in peripheral blood of captive juvenile rhesus macaques (Macaca mulatta) was observed following rotavirus infection. These cell-mediated immune responses were measured following experimental or natural infection after rotavirus was isolated from stool specimens of asymptomatic animals. The virus isolated was a new strain of simian rotavirus that we named TUCH (for Tulane University and Cincinnati Children's Hospital). Restimulation of peripheral T lymphocytes by inactivated double-or triple-layered TUCH rotavirus particles containing either VP6 or VP4 and VP7 on their respective surfaces resulted in increased quantities of interleukin-6 (IL-6) and IL-12 in cell culture supernatants. Recall responses to rotavirus by CD4 ؉ and CD8 ؉ T lymphocytes were associated with accumulation of intracellular IL-6 and gamma interferon. Antigen presentation of TUCH rotavirus to lymphocytes was mediated via differentiated cultures of monocyte-derived dendritic (HLA-DR ؉ ) cells. This is the first report demonstrating cell-mediated immune responses to rotavirus in nonhuman primates. Further exploration of rhesus macaques in vaccine trials with human rotavirus vaccine candidates is the major objective of future studies.In the United States, rotavirus infection of 6-to 36-monthold children results in more than 50,000 hospitalizations each year (41). Throughout the world, at least 500,000 children die annually due to rotavirus-induced dehydration (25,28,41). Although extensive trials of novel vaccine candidates were performed with gnotobiotic piglets or genetically defined mice (28,41,44), none of these candidates have been evaluated in primates. Therefore, development of a nonhuman primate (NHP) model for evaluation of human rotavirus vaccine candidates is urgently needed. Although several NHP species, including chimpanzees and baboons as well as rhesus, vervet, pigtailed, and squirrel monkeys, have been reported to seroconvert to rotavirus with high, virus-specific antibody titers, no studies on cell-mediated immune responses have been conducted with an NHP model in the context of rotavirus (11,14,29,36,43). One reason is that clinical disease associated with rotavirus infection in NHPs, which has been reported to be limited to the first days or weeks of life (20,21,29,36,42), is difficult to produce experimentally.In this study, the cell-mediated immunological responses to rotavirus infection in juvenile rhesus macaques that were housed in biosafety level 2 facilities of the Tulane National Primate Research Center (TNPRC) were evaluated. We anticipated that cell-mediated immune responses could be measured in these animals by the time passive maternally acquired immunity subsided, i.e., at between 4 and 6 months of age. Thus, we studied the T lymphocytes collected from peripheral blood of juvenile rhesus macaques after a detectable rotavirus infection. Based on recent studies with the adult mouse model (4, 5, 24), our hypothesis was that immunological memory in rotav...

Virus-specific intestinal IFN-γ producing T cell responses induced by human rotavirus infection and vaccines are correlated with protection against rotavirus diarrhea in gnotobiotic pigs

“…Recent studies of T cell responses in human PBL showed that in rotavirus infected children, virus-specific CD4+ and CD8+ T cells that secreted IFN-γ were very low or undetectable [19,49]. Similar results were found in studies of rotavirus-infected juvenile rhesus macaques monkeys [50]. Studies of intestinal and systemic rotavirus-specific ASC and lymphocyte proliferation responses in Gn pigs at various time points indicated that blood mirrored the IgA ASC and lymphocyte proliferation responses in the gut, but at a lower level, and could serve as a temporary "window" for monitoring intestinal immune responses to rotavirus.…”

“…The virus titers were determined using a cell culture immunofluorescence (CCIF) assay [3]. The 50% infectious dose (ID 50 ) and diarrhea dose (DD 50 ) of Wa VirHRV was determined previously in Gn pigs as ≤1 FFU [37]. The 37th cell culture passage of Wa AttHRV was propagated in the African green monkey kidney cell line MA104 and used for vaccination at a dose of 5×10 7 FFU and as stimulating antigen (HRV antigen) in intracellular cytokine staining of IFN-γ producing or proliferating T cells.…”

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

“…The ages of the macaques on their day of inoculation are specified in Table 6. Shedding data for macaques FB82, FB88, and FB97 were already provided in tabular form in a very recent publication (39).…”

Interaction of Rotavirus with Human Myeloid Dendritic Cells

“…7). The presence of IL-12 has been reported in the supernatants of cultures of simian DC treated with RV and T cells (52).…”

“…We have previously shown that human monocytes treated in vitro with RV are able to present antigen to specific CD4 ϩ T cells (48). Recently, it was also reported that DC treated with RV can stimulate RV-specific T cells from rhesus macaques (52). Our knowledge of the APC that probably present RV antigen in vivo comes from animal models: viral antigen has been detected in the Peyer's patches, mesenteric lymph nodes, and spleens of mice up to 20 days after RV infection (8).…”