Project description:The SIVmac251 macaque model has been used to evaluate the efficacy of vaccine for HIV. Exposure of macaques to a single high dose of SIVmac251 results in transmission of multiple viral variants, which contrasts the few HIV variants typically transmitted in humans. In here, we investigated whether the dose of SIVmac251 challenge affected vaccination efficacy and found that exposure of the immunized macaques to single high dose of SIVmac251 resulted in no vaccine efficacy, whereas exposure to a tenfold lower dose resulted in protection from SIVmac251 acquisition and protection from disease in animals that become infected. The dose of challenge did not affect the expression of inflammatory genes in the gut in acute infection, but at set point, a significant down regulation of interferon responsive genes and up regulation of genes involved in B and T-cell responses, was observed only in vaccinated animals exposed to a lower dose of SIVmac251. Accordingly, in these animals, we also found a significant correlation with vaccine induced T-cell responses and protection from disease. These data demonstrate that the evaluation of the efficacy of vaccine candidates for HIV relies on accurate modeling in macaques to better mimic HIV transmission to humans. A total of 31 RNA samples were hybridized on to Rhesus Affymetrix 3' Expression arrays. The study was composed of 8 vaccinated and 10 control animals subjected to a low dose challenge and 6 vaccinated and 7 control animals subjected to a high dose challenge
Project description:The SIVmac251 macaque model has been used to evaluate the efficacy of vaccine for HIV. Exposure of macaques to a single high dose of SIVmac251 results in transmission of multiple viral variants, which contrasts the few HIV variants typically transmitted in humans. In here, we investigated whether the dose of SIVmac251 challenge affected vaccination efficacy and found that exposure of the immunized macaques to single high dose of SIVmac251 resulted in no vaccine efficacy, whereas exposure to a tenfold lower dose resulted in protection from SIVmac251 acquisition and protection from disease in animals that become infected. The dose of challenge did not affect the expression of inflammatory genes in the gut in acute infection, but at set point, a significant down regulation of interferon responsive genes and up regulation of genes involved in B and T-cell responses, was observed only in vaccinated animals exposed to a lower dose of SIVmac251. Accordingly, in these animals, we also found a significant correlation with vaccine induced T-cell responses and protection from disease. These data demonstrate that the evaluation of the efficacy of vaccine candidates for HIV relies on accurate modeling in macaques to better mimic HIV transmission to humans. A total of 34 RNA samples were hybridized on to Rhesus Affymetrix 3' Expression arrays. The study was composed of 9 vaccinated and 9 control animals subjected to a low dose challenge and 7 vaccinated and 9 control animals subjected to a high dose challenge
Project description:The absence of a robust disease model currently hinders the evaluation of countermeasures for Middle East respiratory syndrome coronavirus (MERS-CoV). While a rhesus macaque model of MERS-CoV that results in mild-to-moderate disease has been utilized to describe the pathogenesis of this virus and for the evaluation of therapeutics, the inability to produce uniform disease with substantial virus replication complicates analysis in countermeasure studies. In an attempt to identify a more robust disease model, DPP4 sequences of various non-human primates were aligned. Modeling of the interactions between the receptor binding domain of MERS-CoV and its cognate receptor DPP4 predicted a "good fit" with complete conservation of all of the critical residues. To determine the feasibility of the marmoset as a MERS-CoV disease model, common marmosets were inoculated with MERS-CoV via combined intratracheal, intranasal, oral and ocular routes. Marmosets developed signs of moderate to severe illness with progressive serious to severe pneumonia. Progressive gross lesions were evident in animals necropsied at 3, 4 and 6 days post inoculation and two animals were euthanized during the study due to disease severity. This is the first description of a moderate-to-severe, with potentially lethality, disease model of MERS-CoV and as such will have utility for vaccine and other countermeasure efficacy evaluations in addition to further pathogenesis studies. Lung tissue samples were isolated and sequenced at 3, 4 and 6 days post inoculation. Two animals were euthanized during the study due to disease severity.
Project description:The absence of a robust disease model currently hinders the evaluation of countermeasures for Middle East respiratory syndrome coronavirus (MERS-CoV). While a rhesus macaque model of MERS-CoV that results in mild-to-moderate disease has been utilized to describe the pathogenesis of this virus and for the evaluation of therapeutics, the inability to produce uniform disease with substantial virus replication complicates analysis in countermeasure studies. In an attempt to identify a more robust disease model, DPP4 sequences of various non-human primates were aligned. Modeling of the interactions between the receptor binding domain of MERS-CoV and its cognate receptor DPP4 predicted a "good fit" with complete conservation of all of the critical residues. To determine the feasibility of the marmoset as a MERS-CoV disease model, common marmosets were inoculated with MERS-CoV via combined intratracheal, intranasal, oral and ocular routes. Marmosets developed signs of moderate to severe illness with progressive serious to severe pneumonia. Progressive gross lesions were evident in animals necropsied at 3, 4 and 6 days post inoculation and two animals were euthanized during the study due to disease severity. This is the first description of a moderate-to-severe, with potentially lethality, disease model of MERS-CoV and as such will have utility for vaccine and other countermeasure efficacy evaluations in addition to further pathogenesis studies.