Project description:Dendritic cells (DC) serve a key function in host defense, linking innate detection of microbes to the activation of pathogen-specific adaptive immune responses. Whether there is cell-intrinsic recognition of HIV-1 by host innate pattern-recognition receptors and subsequent coupling to antiviral T cell responses is not yet known. DC are largely resistant to infection with HIV-1, but facilitate infection of co-cultured T-helper cells through a process of trans-enhancement. We show here that, when DC resistance to infection is circumvented, HIV-1 induces DC maturation, an antiviral type I interferon response and activation of T cells. This innate response is dependent on the interaction of newly-synthesized HIV-1 capsid (CA) with cellular cyclophilin A (CypA) and the subsequent activation of the transcription factor IRF3. Because the peptidyl-prolyl isomerase CypA also interacts with CA to promote HIV-1 infectivity, our results suggest that CA conformation has evolved under opposing selective pressures for infectivity versus furtiveness. Thus, a cell intrinsic sensor for HIV-1 exists in DC and mediates an antiviral immune response, but it is not typically engaged due to absence of DC infection. The virulence of HIV-1 may be related to evasion of this response, whose manipulation may be necessary to generate an effective HIV-1 vaccine. We analyzed the gene expression profiles of uninfected human monocyte-derived dendritic cells (MDDCs) and MDDCs infected with an envelope-defective GFP-encoding VSV-G-pseudotyped HIV-1 vector (HIVGFP(G)) and with VSV-G pseudotyped virus-like particles derived from SIVmac to deliver Vpx (SIVVLP(G)), alone or in combination. Cells were infected at day 4 of differentiation and cells were harvested 48 hours later. RNA was extracted with TRIzol. RNA was labeled and hybridized to Human Genome U133A 2.0 arrays arrays following the Affymetrix protocols. Data were analyzed in R and Bioconductor.
Project description:Dendritic cells (DC) serve a key function in host defense, linking innate detection of microbes to the activation of pathogen-specific adaptive immune responses. Whether there is cell-intrinsic recognition of HIV-1 by host innate pattern-recognition receptors and subsequent coupling to antiviral T cell responses is not yet known. DC are largely resistant to infection with HIV-1, but facilitate infection of co-cultured T-helper cells through a process of trans-enhancement. We show here that, when DC resistance to infection is circumvented, HIV-1 induces DC maturation, an antiviral type I interferon response and activation of T cells. This innate response is dependent on the interaction of newly-synthesized HIV-1 capsid (CA) with cellular cyclophilin A (CypA) and the subsequent activation of the transcription factor IRF3. Because the peptidyl-prolyl isomerase CypA also interacts with CA to promote HIV-1 infectivity, our results suggest that CA conformation has evolved under opposing selective pressures for infectivity versus furtiveness. Thus, a cell intrinsic sensor for HIV-1 exists in DC and mediates an antiviral immune response, but it is not typically engaged due to absence of DC infection. The virulence of HIV-1 may be related to evasion of this response, whose manipulation may be necessary to generate an effective HIV-1 vaccine.
Project description:A growing body of data suggests that the human brain serves as a sanctuary for HIV persistence despite life-long antiretroviral therapy. Microglia, the innate immune cells of the brain parenchyma, may serve as a reservoir for rebound of HIV infection. The extent of the latent brain reservoir and molecular phenotype of HIV infected microglia cells, however, are unknown. To address this major knowledge gap, we leveraged the ‘Last Gift’ rapid autopsy cohort to perform a multi-omics approach (single cell RNA-seq, single cell ATAC-seq, and H3K27ac ChIP-seq) of the myeloid compartment creating a gene expression and chromatin accessibility atlas of human microglia isolated from three male individuals with HIV on suppressive antiretroviral therapy.
Project description:A growing body of data suggests that the human brain serves as a sanctuary for HIV persistence despite life-long antiretroviral therapy. Microglia, the innate immune cells of the brain parenchyma, may serve as a reservoir for rebound of HIV infection. The extent of the latent brain reservoir and molecular phenotype of HIV infected microglia cells, however, are unknown. To address this major knowledge gap, we leveraged the ‘Last Gift’ rapid autopsy cohort to perform a multi-omics approach (single cell RNA-seq, single cell ATAC-seq, and H3K27ac ChIP-seq) of the myeloid compartment creating a gene expression and chromatin accessibility atlas of human microglia isolated from three male individuals with HIV on suppressive antiretroviral therapy.
Project description:A growing body of data suggests that the human brain serves as a sanctuary for HIV persistence despite life-long antiretroviral therapy. Microglia, the innate immune cells of the brain parenchyma, may serve as a reservoir for rebound of HIV infection. The extent of the latent brain reservoir and molecular phenotype of HIV infected microglia cells, however, are unknown. To address this major knowledge gap, we leveraged the ‘Last Gift’ rapid autopsy cohort to perform a multi-omics approach (single cell RNA-seq, single cell ATAC-seq, and H3K27ac ChIP-seq) of the myeloid compartment creating a gene expression and chromatin accessibility atlas of human microglia isolated from three male individuals with HIV on suppressive antiretroviral therapy.
Project description:This SuperSeries is composed of the following subset Series: GSE22768: Systems analysis of the Merck Ad5/HIV vaccine reveals robust induction of a core innate immune gene network: in vivo analysis GSE22769: Systems analysis of the Merck Ad5/HIV vaccine reveals robust induction of a core innate immune gene network: in vitro analysis To better understand how innate immune responses to vaccination can lead to lasting protective immunity, we used a systems approach to define immune signatures in humans over 1 wk following MRKAd5/HIV vaccination that predicted subsequent HIV-specific T-cell responses. Within 24 h, striking increases in peripheral blood mononuclear cell gene expression associated with inflammation, IFN response, and myeloid cell trafficking occurred, and lymphocyte-specific transcripts decreased. These alterations were corroborated by marked serum inflammatory cytokine elevations and egress of circulating lymphocytes. Responses of vaccinees with preexisting adenovirus serotype 5 (Ad5) neutralizing antibodies were strongly attenuated, suggesting that enhanced HIV acquisition in Ad5-seropositive subgroups in the Step Study may relate to the lack of appropriate innate activation rather than to increased systemic immune activation. Importantly, patterns of chemoattractant cytokine responses at 24 h and alterations in 209 peripheral blood mononuclear cell transcripts at 72 h were predictive of subsequent induction and magnitude of HIV-specific CD8(+) T-cell responses. This systems approach provides a framework to compare innate responses induced by vectors, as shown here by contrasting the more rapid, robust response to MRKAd5/HIV with that to yellow fever vaccine. When applied iteratively, the findings may permit selection of HIV vaccine candidates eliciting innate immune response profiles more likely to drive HIV protective immunity. Refer to individual Series