Project description:Natural SIV infection of sooty mangabeys (SMs) does not progress to disease despite chronic virus replication. In contrast to pathogenic SIV infection of rhesus macaques (RMs), chronic SIV infection of SMs is characterized by low immune activation. To elucidate the mechanisms underlying this phenotype, we longitudinally assessed host gene expression in SIV-infected SMs and RMs. We found that acute SIV infection of SMs is consistently associated with a robust innate immune response, including widespread up-regulation of interferon-stimulated genes (ISGs). Our findings indicate that active immune regulatory mechanisms, rather than intrinsically attenuated innate immune responses, underlie the low immuneactivation of chronically SIV-infected SMs. We infected 5 SMs with SIVsmm and assessed their gene expression in RNA derived from whole blood at 3,7,10,14,30 and 180 days post-infection using Rhesus Affymetrix GeneChips. As a comparison, we also analyzed gene expression in 4 RMs infected with SIVsmm, and 8 RMs infected with SIVmac239, a classical pathogenic SIV.
Project description:This study describes differential miRNA expression in intact colon tissue during acute SIV infection of rhesus macaques. Nine miRNAs were found to be significantly affected by infection, with 5 down-regulated and 4 up-regulated miRNAs. The expression of one upregulated miRNA was further characterized and found to be significantly elevated specifically in response to SIV replication and not immune activation/inflammation accompanying SIV infection. We performed TaqMan Low Density Array based high throughput miRNA analysis on intact colon tissue from 10 acutely SIV-infected and 5 uninfected control macaques. All SIV-infected animals were inoculated intravenously with 100TCID50 of SIV. Out of the ten, one animal each was at 7, 8 and 10DPI (days post infection), 3 each at 13 and 21DPI, and 1 at 29DPI. microRNA reverse transcription and preamplification was performed according to the manufacturerM-bM-^@M-^Ys recommendation. Data analysis was performed using RQ Manager 1.2.2 and DataAssist v3.01 software. Data was normalized using Global normalization method and multiple comparisons correction was performed using Benjamini-Hochberg method.
Project description:The study describes miRNA expression in colonic epithelium of chronic SIV-infected rhesus macaques. We profiled and characterized miRNA/mRNA expression exclusively in colonic epithelium (CE) of 12 chronically SIV-infected and 8 control rhesus macaques (RMs). About 46 miRNAs were differentially expressed (DE) (20-up and 26-down) in CE during chronic SIV infection. Using TargetScan, we bioinformatically crossed the predicted targets of DE miRNAs to genome-wide transcriptomic data and identified several critical miRNA-mRNA pairings that suggested miRNA-mediated regulation of aberrant epithelial gene expression in CE. Immunofluorescence, luciferase reporter and miRNA overexpression studies confirmed the ability of miR-130a and miR-212 to bind the 3’ UTR and downregulate protein expression of occludin (OCLN) and peroxisome proliferator activator receptor gamma (PPAR), respectively, two proteins with pivotal roles in epithelial barrier function. MiR-130a and miR-212 overexpression in Caco-2 cells significantly reduced transepithelial electrical resistance (TEER). Interestingly, delta-9-tetrahydrocannabinol (9-THC) treatment restored TEER to levels observed with control miRNA mimic. Finally, ex-vivo 9-THC treatment of colon tissue from chronically SIV-infected RMs significantly increased PPAR gene expression. Our findings suggest that dysregulated miR-130a and miR-212 expression in CE during chronic HIV/SIV infection can facilitate epithelial barrier disruption by downregulating OCLN and PPAR protein expression. Most importantly, our results highlight the beneficial effects of cannabinoids on epithelial barrier function in not just HIV/SIV but potentially other chronic intestinal inflammatory diseases.
Project description:Immunization of macaques with simian immunodeficiency virus with deletions in nef (SIV?nef) has been shown to elicit protective immunity to infection by pathogenic SIV, yet our understanding of the mechanisms that orchestrate protection and prevent pathogenesis remains limited. In the study, we utilize whole-genome transcriptional profiling to reveal molecular signatures of protective immunity in circulating CD8+ T cells of rhesus macaques vaccinated with SIVmac239?nef and challenged with pathogenic SIVmac251. Microarrays were used to characterize changes in gene expression in blood CD8+ T cells that occur following vaccination of rhesus macaques with attenuated SIV?nef and subsequent challenge with pathogenic SIVmac251, in comparison to corresponding changes in healthy controls and unvaccinated animals infected with pathogenic SIVmac251 CD8+ T cells were isolated by magnetic beads from the blood of healthy uninfected macaques, macaques vaccinated with SIV?nef, and unvaccinated controls infected with SIVmac251, and used for RNA extraction and hybridization on Affymetrix microarrays. Blood samples from vaccinated animals were collected prior to vaccination, at 3, 20, and 40 weeks following vaccination. After the 40 week vaccination period, macaques were challenged with SIVmac251, and blood was again collected at 3 weeks following challenge. Blood was collected from the unvaccinated controls at 3 weeks following infection with SIVmac251
Project description:Rhesus macaques (RMs) inoculated with live-attenuated Rev-Independent Nef¯ simian immunodeficiency virus (Rev-Ind Nef¯SIV) as adults or neonates controlled viremia to undetectable levels and showed no signs of immunodeficiency over 6-8 years of follow-up. We tested the capacity of this live-attenuated virus to protect RMs against pathogenic, heterologous SIVsmE660 challenges Blood PBMC Time after SIV infection: 2 weeks post SIV infection Infection:Rev-Ind Nef¯SIV
Project description:This study describes differential miRNA expression in intact colon tissue during acute SIV infection of rhesus macaques. Nine miRNAs were found to be significantly affected by infection, with 5 down-regulated and 4 up-regulated miRNAs. The expression of one upregulated miRNA was further characterized and found to be significantly elevated specifically in response to SIV replication and not immune activation/inflammation accompanying SIV infection.