Project description:Antiretroviral therapy can effectively block HIV-1 replication and prevent or reverse immunodeficiency in HIV-1-infected individuals. However, viral replication resumes within weeks of treatment interruption. The major barrier to a cure is a small pool of resting memory CD4+ T cells that harbor latent HIV-1 proviruses. This latent reservoir is now the focus of an intense international research effort. We describe how the reservoir is established, challenges involved in eliminating it, and pharmacologic and immunologic strategies for targeting this reservoir. The development of a successful cure strategy will most likely require understanding the mechanisms that maintain HIV-1 proviruses in a latent state and pathways that drive the proliferation of infected cells, which slows reservoir decay. In addition, a cure will require the development of effective immunologic approaches to eliminating infected cells. There is renewed optimism about the prospect of a cure, and the interventions discussed here could pave the way.
Project description:Antiretroviral therapy (ART) is not curative due to the existence of cellular reservoirs of latent HIV-1 that persist during therapy 1. Current research efforts to cure HIV-1 infection include “shock and kill” strategies to disrupt latency using small molecules or latency-reversing agents (LRAs) to induce expression of HIV-1 enabling cytotoxic immune cells to eliminate infected cells 2. However, the modest success of current LRAs urges the field to identify novel drugs with increased clinical efficacy 3,4. Aminobisphosphonates that include pamidronate, zoledronate, or alendronate, are the first-line treatment of bone-related diseases including osteoporosis and bone malignancies 5. Here, we show the use of aminobisphosphonates as a novel class of LRA: we found in ex vivo assays using primary cells from ART-suppressed people living with HIV-1 that aminobisphosphonates induce HIV-1 from latency to levels that are comparable to the T cell activator phytohemagglutinin. RNA sequencing and mechanistic data suggested that reactivation may occur through activation of the activator protein 1 signaling pathway. Stored samples from a prior clinical trial aimed at analyzing the effect of alendronate on bone mineral density, provided further of alendronate-mediated latency reversal and activation of immune effector cells.Decay of the reservoir measured by IPDA was however not detected. Our results demonstrate the novel use of aminobisphosphonates to reverse HIV-1 latency while inducing immune effector functions. This preliminary evidence merits further investigation in a controlled clinical setting possibly in combination with therapeutic vaccination.
Project description:The latent reservoir (LR) of HIV-1 in resting memory CD4(+) T cells serves as a major barrier to curing HIV-1 infection. While many PCR- and culture-based assays have been used to measure the size of the LR, correlation between results of different assays is poor and recent studies indicate that no available assay provides an accurate measurement of reservoir size. The discrepancies between assays are a hurdle to clinical trials that aim to measure the efficacy of HIV-1 eradication strategies. Here we describe the advantages and disadvantages of various approaches to measuring the LR.
Project description:Enhanced human immunodeficiency virus (HIV)-specific immunity may be required for HIV eradication. Administration of autologous, ex vivo expanded, virus-specific, cytotoxic T-lymphocytes derived from HIV-infected patients on suppressive antiretroviral therapy (HXTCs) are a powerful tool for proof-of-concept studies. Broadly specific, polyclonal HXTCs resulting from ex vivo expansion demonstrated improved control of autologous reservoir virus compared to bulk CD8(+) T cells in viral inhibition assays. Furthermore, patient-derived HXTCs were able to clear latently infected autologous resting CD4(+) T cells following exposure to the latency-reversing agent, vorinostat. HXTCs will be ideal reagents to administer with precise control in future in vivo studies in combination with latency-reversing agents.
Project description:HIV-1 infection cannot be cured because the virus persists as integrated proviral DNA in long-lived cells despite years of suppressive antiretroviral therapy (ART). In a previous paper (Zanini et al, 2015) we documented HIV-1 evolution in 10 untreated patients. Here we characterize establishment, turnover, and evolution of viral DNA reservoirs in the same patients after 3-18 years of suppressive ART. A median of 14% (range 0-42%) of the DNA sequences were defective due to G-to-A hypermutation. Remaining DNA sequences showed no evidence of evolution over years of suppressive ART. Most sequences from the DNA reservoirs were very similar to viruses actively replicating in plasma (RNA sequences) shortly before start of ART. The results do not support persistent HIV-1 replication as a mechanism to maintain the HIV-1 reservoir during suppressive therapy. Rather, the data indicate that DNA variants are turning over as long as patients are untreated and that suppressive ART halts this turnover.
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:While antiretroviral therapy (ART) has effectively revolutionized HIV care, the virus is never fully eliminated. Instead, immune dysfunction, driven by persistent non-specific immune activation, ensues and progressively leads to premature immunologic aging. Current biomarkers monitoring immunologic changes encompass generic inflammatory biomarkers, that may also change with other infections or disease states, precluding the antigen-specific monitoring of HIV-infection associated changes in disease. Given our growing appreciation of the significant changes in qualitative and quantitative properties of disease-specific antibodies in HIV infection, we used a systems approach to explore humoral profiles associated with HIV control. We found that HIV-specific antibody profiles diverge by spontaneous control of HIV, treatment status, viral load and reservoir size. Specifically, HIV-specific antibody profiles representative of changes in viral load were largely quantitative, reflected by differential HIV-specific antibody levels and Fc-receptor binding. Conversely, HIV-specific antibody features that tracked with reservoir size exhibited a combination of quantitative and qualitative changes marked by more distinct subclass selection profiles and unique HIV-specific Fc-glycans. Our analyses suggest that HIV-specific antibody Fc-profiles provide antigen-specific resolution on both cell free and cell-associated viral loads, pointing to potentially novel biomarkers to monitor reservoir activity.