Project description:Understanding the complexity of the long-lived HIV reservoir during antiretroviral therapy (ART) remains a major impediment for HIV cure research. To address this, we developed single-cell viral ASAPseq to precisely define the unperturbed peripheral blood HIV-infected memory CD4+ T cell reservoir from antiretroviral treated people living with HIV (ART-PLWH) via the presence of integrated accessible proviral DNA in concert with epigenetic and cell surface protein profiling. We identified profound reservoir heterogeneity within and between ART-PLWH, characterized by novel and known surface markers within total and individual memory CD4+ T cell subsets. We further uncovered novel epigenetic profiles and transcription factor motifs enriched in HIV-infected cells that suggest infected cells with accessible provirus, irrespective of reservoir distribution, are poised for reactivation during ART treatment. Together, our findings reveal the extensive inter- and intrapersonal cellular heterogeneity of the HIV reservoir, and establish an initial multiomic atlas to develop targeted reservoir elimination strategies.
Project description:During HIV infection, a latent viral reservoir is formed that persists during antiretroviral therapy (ART) and is maintained by a heritable state of transcriptional repression. Recent findings indicate that much of the reservoir originates from infections occurring in the weeks near the time of ART initiation, raising the important possibility that interventions during this period might prevent reservoir seeding and substantially reduce reservoir size. Based on this concept, we tested the ability of compounds that target epigenetic machinery to prevent the establishment of latent HIV infection in primary CD4 T cells. We identified class 1 histone deacetylase inhibitors (HDACi) as potent agents of latency prevention, an activity distinct from latency reversal. Inhibiting HDACs in productively infected cells caused extended maintenance of HIV expression, even after HDACi withdrawal, and this activity was associated with persistently elevated H3K9 acetylation and reduced H3K9 methylation at the viral LTR promoter region. HDAC inhibition in HIV-infected CD4 T cells during effector-to-memory transition led to a striking change in the memory subset distribution indicating reprogramming of cell identity. Through knockout of individual HDACs and use of HDAC-selective inhibitors, we determined that HDAC1 and HDAC3 play crucial and distinct roles in proviral silencing initiation. Overall, this work indicates that a network of HDACs regulate a critical gateway process for HIV latency establishment and are required for the development of CD4 T-cell memory subsets that preferentially harbor long-lived, latent provirus. Epigenetic reprogramming by clinical targeting of HDACs during ART initiation may represent a novel way to prevent seeding of the HIV reservoir in vivo
Project description:This study compared the subgingival microbiota of subjects with periodontitis to those with periodontal health using the Human Oral Microbe Identification Microarray (HOMIM).
Project description:The Lyme disease spirochete Borrelia burgdorferi drives a range of acute and chronic maladies in humans and other incidental hosts infected with the pathogen. However, the primary vertebrate reservoir, Peromyscus leucopus appears spared from any symptomology following infection. This has led to a common hypothesis that P. leucopus and B. burgdorferi exist symbiotically: P. leucopus restrain their immune response against the microbe and enable the enzootic cycle while B. burgdorferi avoids causing damage to the host. While aspects of this hypothesis have been tested, the exact interactions that occur between P. leucopus and B. burgdorferi during infection remain largely unknown. Here we utilized an inbred colony of P. leucopus in order to compare B. burgdorferi (B31) fitness in these rodents to the traditional B. burgdorferi murine models—C57BL/6J and C3H/HeN Mus musculus, which develop signs of inflammation akin to human disease. We find that in contrast to our expectations, B. burgdorferi were able to reach much higher burdens in M. musculus, and that the overall kinetics of infection differed between the two rodent species. Surprisingly, we also found that P. leucopus remained infectious to larval Ixodes scapularis for a far shorter period than either M. musculus strain. In line with these observations, we found that P. leucopus does launch a modest but sustained inflammatory response against B. burgdorferi in the skin, which we hypothesize leads to reduced bacterial viability and infectivity in these hosts. These observations provide new insight into the nature of reservoir species and the B. burgdorferi enzootic cycle.
Project description:Despite antiretroviral therapy, HIV mainly persists in memory CD4+ T cells in people living with HIV. Most long-lived viral reservoir cells are infected near the time of therapy initiation. A better understanding of the early events in reservoir seeding presents opportunities for preventing latent reservoir formation. Here, we demonstrated that CD4+ T cells expressing CCR5, permissive to HIV-1 infection, are effector or terminally differentiated cells. BACH2 is expressed by a small subset of CCR5+ cells and reverses their terminal differentiation. BACH2-mediated memory differentiation is impeded due to heightened inflammation before treatment initiation. Mice with a BACH2 knockout human immune system has a reduced frequency of HIV-1 reservoir cells and do not experience virus rebound after treatment discontinuation. Our study reveals that BACH2 is essential to the seeding of long-lived HIV-1 reservoir and demonstrates the potential of targeting BACH2 at the time of treatment initiation to eliminate HIV-1 reservoirs in T cells.
Project description:To identify chromatin alterations by host-microbe interactions in cervicovaginal epithelial cells we performed ATAC-sequencing. We identified regions of chromatin that were altered in cervicovaginal epithelial cells after exposure to L. crispatus supernatant.
Project description:To investigate the function of field extracellular vesicles (EVs) from Xinglinwan Reservoir, which is located in Jimei area, Xiamen, Fujian province. We also traced their taxon sources and their distributions across one year of the reservoir.
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.