This SuperSeries is composed of the SubSeries listed below.
No associated publication
Specimen part, Treatment, Subject, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Protection afforded by an HIV vaccine candidate in macaques depends on the dose of SIVmac251 at challenge exposure.
Specimen part
View SamplesCD8+ T-cells inhibit virus replication in SIV-infected rhesus macaques (RM). However, it is unclear to what extent the viral suppression mediated by CD8+ T-cells reflects direct killing of infected cells as opposed to indirect, non-cytolytic mechanisms. In this study, we used functional genomics to investigate potential mechanisms of in vivo viral suppression mediated by CD8+ lymphocytes. Eight chronically SIVmac239-infected RMs underwent CD8+ lymphocyte depletion, and RNA from whole blood was obtained prior to depletion, at the nadir of CD8+ lymphocytes (5 days post-depletion), and during the repopulation phase (11 days post-depletion). Principal components analysis demonstrated that overall gene expression during the nadir of CD8+ T-cells was highly divergent from other intervals. Conversely, the genomic signature of samples from the CD8+ cell rebound phase was similar to that of pre-depletion samples. During CD8+ lymphocyte depletion we detected a strongly significant decrease in the expression of the genes encoding CD8 and CD8 chains, consistent with the near complete CD8+ T-cell depletion measured by flow cytometry. Of note, we observed significant down-regulation of the expression of genes encoding for factors that can suppress SIV replication, including the CCR5-binding chemokine CCL5/Rantes, several retroviral restriction factors (TRIM10, TRIM15, APOBEC3G/H) and defensins. Reduced expression of various genes related to T cell activation and proliferation was also observed. Collectively, these data indicate that depletion of CD8+ lymphocytes in SIV-infected RMs is associated with the establishment of a pattern of gene expression that may result in increased intrinsic permissivity to virus replication.
Transcriptional profiling of experimental CD8(+) lymphocyte depletion in rhesus macaques infected with simian immunodeficiency virus SIVmac239.
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View SamplesACTG A5258, we asked whether chloroquine could reduce the immune activation in HIV infection posited to be driven by microbial TLR agonists, such as bacterial elements translocated from the gut and HIV-1 RNAs . We anticipate that blocking this activation pathway might interfere with events in pathogenesis leading to AIDS- and non-AIDS-related clinical manifestations of HIV disease.
No associated publication
Specimen part, Treatment, Subject, Time
View SamplesACTG A5258, we asked whether chloroquine could reduce the immune activation in HIV infection posited to be driven by microbial TLR agonists, such as bacterial elements translocated from the gut and HIV-1 RNAs . We anticipate that blocking this activation pathway might interfere with events in pathogenesis leading to AIDS- and non-AIDS-related clinical manifestations of HIV disease.
No associated publication
Specimen part, Treatment, Subject, Time
View SamplesThe 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.
Protection afforded by an HIV vaccine candidate in macaques depends on the dose of SIVmac251 at challenge exposure.
Specimen part
View SamplesThe 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.
Protection afforded by an HIV vaccine candidate in macaques depends on the dose of SIVmac251 at challenge exposure.
Specimen part
View SamplesMaternal innate and adaptive immune responses are modulated during pregnancy to concurrently defend against infection and tolerate the semi-allogeneic fetus. The restoration of these systems after childbirth is poorly understood. We reasoned that enhanced innate immune activation may extend beyond gestation while adaptive immunity recovers. To test this hypothesis, the transcriptional profiles of total PBMCs following delivery in healthy women were compared to those of non-pregnant control subjects. Interestingly, interferon stimulated genes (ISGs) encoding proteins such as IFIT1, IFIT2, and IFIT3, as well as signaling proteins such as STAT1, STAT2, and MAVS, were enriched postpartum. Antiviral genes were primarily expressed in CD14+ cells and could be stratified according to genetic variation at the interferon-3 gene (IFNL3, also named IL28B) single nucleotide polymorphism (SNP) rs12979860. Antiviral gene expression was sustained beyond six months following delivery in mothers with a CT or TT genotype but resembled baseline non-pregnant control levels following delivery in mothers with a CC genotype. CT and TT IFNL3 genotypes have been associated with persistent elevated ISG expression in individuals chronically infected with hepatitis C virus. Together these data suggest that postpartum, the normalization of the physiological rheostat controlling interferon signaling is dependent on IFNL3 genotype.
Prolonged activation of innate antiviral gene signature after childbirth is determined by IFNL3 genotype.
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View SamplesWe assessed correlates of protection from disease progression in a rare subset of HIV-infected individuals, viremic non-progressors (VNPs). These individuals have high viral load for several years, but in contrast to the majority of infected individuals, they do not progress to AIDS. Here we found this lack of progression was associated with selective preservation of two essential subsets of memory CD4+ T cells, central memory (TCM) and stem-cell memory (TSCM) cells. Compared to HIV-infected putative progressors, VNPs had higher proliferation of these indispensable subsets of memory cells, which was associated with the number of TCM. In addition, the long-lived CD4+ TCM and TSCM cells in VNPs had decreased HIV infection compared to the less critical effector memory CD4+ T cells, which indicates a possible mechanism by which VNPs maintain their CD4+ T cell pool after several years of infection, and remain free from AIDS progression.
No associated publication
Specimen part
View SamplesCD8+ T-cells inhibit virus replication in SIV-infected rhesus macaques (RM). However, it is not clear how SIV infection is controlled in germinal center during chronic SIV infection and limited information exists on the characteristics of CXCR5+ CD8 T cells during chronic SIV/HIV infection. In this study, we used functional genomics to investigate characteristic features and potential mechanisms of CXCR5+ and CXCR5- SIV specific CD8 T cells for the control of pathogenic SIV infection. Six chronically SIV infected RMs, three SIVE660 infected and three SIV mac251 infected that are positive for Mamu A01 allele were selected and SIV-specific CXCR5+ and CXCR5- CD8 T cells were sorted based on CXCR5 expression. RNA from sorted cells were extracted and microarray were performed and analysed. Principal component analysis demonstrated that overall gene expression difference between CXCR5+ and CXCR5- SIV-specific CD8 T cells. Interestingly, the CXCR5+ CD8 T cells revealed a distinct gene signature pattern when compared to CXCR5- CD8 T cells. Unlike the CXCR5- CD8 T cells, the CXCR5+ CD8 T cells expressed higher levels of genes associated with Tfh CD4 T cells such as the master transcription factor Bcl6, CD200, and CTLA4 as well as markers associated with Th2 CD4 T cells such as IL-4R (CD124), CCR4, STAT6, NFATC, and IL-10. Effector molecules typically observed in cytotoxic CD8 T cells such as granzyme A, B, and K were expressed at lower levels on CXCR5+ CD8 T cells compared to their CXCR5- counterparts. CXCR5+ CD8 T cells also expressed higher levels of molecules associated with co-stimulation/antigen presentation such as CD40, CD83, 41BBL and MAMU-DRA. The CXCR5+ CD8 also expressed higher levels of inhibitory receptors such as CD200 and SPRY2 but lower levels of other inhibitory receptors CD160 and CD244. The functional consequence of the expression of these molecules is yet to be determined. Additionally, CXCR5+ CD8 T cells expressed higher levels of the anti-apoptotic gene Bcl-2 and lower levels of the pro-apoptotic gene annexin, suggestive of their better survival potential during chronic SIV infection. Collectively, these results demonstrate that SIV specific CXCR5+ CD8 T cells possess a unique gene expression signature compared to SIV-specific CXCR5- CD8 T cells.
Dynamics of SIV-specific CXCR5+ CD8 T cells during chronic SIV infection.
Specimen part
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