High levels of genetically intact HIV in HLA-DR+ memory T cells indicates their value for reservoir studies.

ObjectiveThe contribution of HLA-DR+ memory CD4 T cells to the HIV reservoir during prolonged antiretroviral therapy is unclear as these cells are commonly excluded when assessing for replication-competent HIV. To address this issue, we examined the distribution of genetically intact HIV DNA within HLA-DR- and HLA-DR+ memory CD4 T cells and the RNA transcriptional profile of these cells during antiretroviral therapy.Design/methodsFull-length DNA sequencing was used to examine the HIV DNA landscape within HLA-DR+ and HLA-DR- memory CD4 T cells. RNA quantification and sequencing was used to interrogate the relationship between HLA-DR status and HIV RNA transcription.ResultsHLA-DR+ CD4 T cells contained a high frequency of genetically intact HIV genomes, contributing over half of the genetically intact viral sequences to the reservoir. Expansions of genetically identical sequences were identified in all T-cell subsets, indicating that cellular proliferation maintains genetically intact and defective viral DNA during therapy. Intracellular HIV RNA levels in HLA-DR+ and HLA-DR- T cells were not statistically different by either long terminal repeat quantitative PCR quantification or single-genome RNA sequencing of the p6-RT region.ConclusionThe high proportion of intact viral DNA sequences in the proliferative HLA-DR+ subset suggests they are critical in maintaining HIV infection during effective therapy. As such, these cells should be included in any immune intervention targeting HIV during effective therapy

Impact of Antiretroviral Therapy Duration on HIV-1 Infection of T Cells within Anatomic Sites.

Understanding the impact of antiretroviral therapy (ART) duration on HIV-infected cells is critical for developing successful curative strategies. To address this issue, we conducted a cross-sectional/inter-participant genetic characterization of HIV-1 RNA from pre- and on-therapy plasmas and HIV-1 DNA from CD4+ T cell subsets derived from peripheral blood (PB), lymph node (LN), and gut tissues of 26 participants after 3 to 17.8 years of ART. Our studies revealed in four acute/early participants who had paired PB and LN samples a substantial reduction in the proportion of HIV-infected cells per year on therapy within the LN. Extrapolation to all 12 acute/early participants estimated a much smaller reduction in the proportion of HIV-1-infected cells within LNs per year on therapy that was similar to that in the participants treated during chronic infection. LN-derived effector memory T (TEM) cells contained HIV-1 DNA that was genetically identical to viral sequences derived from pre- and on-therapy plasma samples. The proportion of identical HIV-1 DNA sequences increased within PB-derived TEM cells. However, the infection frequency of TEM cells in PB was stable, indicating that cellular proliferation that compensates for T cell loss over time contributes to HIV-1 persistence. This study suggests that ART reduces HIV-infected T cells and that clonal expansion of HIV-infected cells maintains viral persistence. Importantly, LN-derived TEM cells are a probable source of HIV-1 genomes capable of producing infectious HIV-1 and should be targeted by future curative strategies.IMPORTANCE HIV-1 persists as an integrated genome in CD4+ memory T cells during effective therapy, and cessation of current treatments results in resumption of viral replication. To date, the impact of antiretroviral therapy duration on HIV-infected CD4+ T cells and the mechanisms of viral persistence in different anatomic sites is not clearly elucidated. In the current study, we found that treatment duration was associated with a reduction in HIV-infected T cells. Our genetic analyses revealed that CD4+ effector memory T (TEM) cells derived from the lymph node appeared to contain provirus that was genetically identical to plasma-derived virions. Moreover, we found that cellular proliferation counterbalanced the decay of HIV-infected cells throughout therapy. The contribution of cellular proliferation to viral persistence is particularly significant in TEM cells. Our study emphasizes the importance of HIV-1 intervention and provides new insights into the location of memory T cells infected with HIV-1 DNA, which is capable of contributing to viremia

Impact of Antiretroviral Therapy Duration on HIV-1 Infection of T Cells within Anatomic Sites.

Understanding the impact of antiretroviral therapy (ART) duration on HIV-infected cells is critical for developing successful curative strategies. To address this issue, we conducted a cross-sectional/inter-participant genetic characterization of HIV-1 RNA from pre- and on-therapy plasmas and HIV-1 DNA from CD4+ T cell subsets derived from peripheral blood (PB), lymph node (LN), and gut tissues of 26 participants after 3 to 17.8 years of ART. Our studies revealed in four acute/early participants who had paired PB and LN samples a substantial reduction in the proportion of HIV-infected cells per year on therapy within the LN. Extrapolation to all 12 acute/early participants estimated a much smaller reduction in the proportion of HIV-1-infected cells within LNs per year on therapy that was similar to that in the participants treated during chronic infection. LN-derived effector memory T (TEM) cells contained HIV-1 DNA that was genetically identical to viral sequences derived from pre- and on-therapy plasma samples. The proportion of identical HIV-1 DNA sequences increased within PB-derived TEM cells. However, the infection frequency of TEM cells in PB was stable, indicating that cellular proliferation that compensates for T cell loss over time contributes to HIV-1 persistence. This study suggests that ART reduces HIV-infected T cells and that clonal expansion of HIV-infected cells maintains viral persistence. Importantly, LN-derived TEM cells are a probable source of HIV-1 genomes capable of producing infectious HIV-1 and should be targeted by future curative strategies.IMPORTANCE HIV-1 persists as an integrated genome in CD4+ memory T cells during effective therapy, and cessation of current treatments results in resumption of viral replication. To date, the impact of antiretroviral therapy duration on HIV-infected CD4+ T cells and the mechanisms of viral persistence in different anatomic sites is not clearly elucidated. In the current study, we found that treatment duration was associated with a reduction in HIV-infected T cells. Our genetic analyses revealed that CD4+ effector memory T (TEM) cells derived from the lymph node appeared to contain provirus that was genetically identical to plasma-derived virions. Moreover, we found that cellular proliferation counterbalanced the decay of HIV-infected cells throughout therapy. The contribution of cellular proliferation to viral persistence is particularly significant in TEM cells. Our study emphasizes the importance of HIV-1 intervention and provides new insights into the location of memory T cells infected with HIV-1 DNA, which is capable of contributing to viremia

Identification of Genetically Intact HIV-1 Proviruses in Specific CD4+ T Cells from Effectively Treated Participants

Latent replication-competent HIV-1 persists in individuals on long-term antiretroviral therapy (ART). We developed the Full-Length Individual Proviral Sequencing (FLIPS) assay to determine the distribution of latent replication-competent HIV-1 within memory CD4+ T cell subsets in six individuals on long-term ART. FLIPS is an efficient, high-throughput assay that amplifies and sequences near full-length (∼9 kb) HIV-1 proviral genomes and determines potential replication competency through genetic characterization. FLIPS provides a genome-scale perspective that addresses the limitations of other methods that also genetically characterize the latent reservoir. Using FLIPS, we identified 5% of proviruses as intact and potentially replication competent. Intact proviruses were unequally distributed between T cell subsets, with effector memory cells containing the largest proportion of genetically intact HIV-1 proviruses. We identified multiple identical intact proviruses, suggesting a role for cellular proliferation in the maintenance of the latent HIV-1 reservoir

Longitudinal genetic characterization reveals that Cell Proliferation Maintains a Persistent HIV Type 1 DNA Pool During Effective HIV Therapy

 The stability of the human immunodeficiency virus type 1 (HIV-1) reservoir and the contribution of cellular proliferation to the maintenance of the reservoir during treatment are uncertain. Therefore, we conducted a longitudinal analysis of HIV-1 in T-cell subsets in different tissue compartments from subjects receiving effective antiretroviral therapy (ART).status: publishe

Longitudinal Genetic Characterization Reveals That Cell Proliferation Maintains a Persistent HIV Type 1 DNA Pool During Effective HIV Therapy

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Longitudinal Genetic Characterization Reveals That Cell Proliferation Maintains a Persistent HIV Type 1 DNA Pool During Effective HIV Therapy.

BackgroundThe stability of the human immunodeficiency virus type 1 (HIV-1) reservoir and the contribution of cellular proliferation to the maintenance of the reservoir during treatment are uncertain. Therefore, we conducted a longitudinal analysis of HIV-1 in T-cell subsets in different tissue compartments from subjects receiving effective antiretroviral therapy (ART).MethodsUsing single-proviral sequencing, we isolated intracellular HIV-1 genomes derived from defined subsets of CD4(+) T cells from peripheral blood, gut-associated lymphoid tissue and lymph node tissue specimens from 8 subjects with virologic suppression during long-term ART at 2 time points (time points 1 and 2) separated by 7-9 months.ResultsDNA integrant frequencies were stable over time (<4-fold difference) and highest in memory T cells. Phylogenetic analyses showed that subjects treated during chronic infection contained viral populations with up to 73% identical sequence expansions, only 3 of which were observed in specimens obtained before therapy. At time points 1 and 2, such clonally expanded populations were found predominantly in effector memory T cells from peripheral blood and lymph node tissue specimens.ConclusionsMemory T cells maintained a relatively constant HIV-1 DNA integrant pool that was genetically stable during long-term effective ART. These integrants appear to be maintained by cellular proliferation and longevity of infected cells, rather than by ongoing viral replication

Activation of HIV Transcription with Short-Course Vorinostat in HIV-Infected Patients on Suppressive Antiretroviral Therapy

<div><p></p><p>Human immunodeficiency virus (HIV) persistence in latently infected resting memory CD4+ T-cells is the major barrier to HIV cure. Cellular histone deacetylases (HDACs) are important in maintaining HIV latency and histone deacetylase inhibitors (HDACi) may reverse latency by activating HIV transcription from latently infected CD4+ T-cells. We performed a single arm, open label, proof-of-concept study in which vorinostat, a pan-HDACi, was administered 400 mg orally once daily for 14 days to 20 HIV-infected individuals on suppressive antiretroviral therapy (ART). The primary endpoint was change in cell associated unspliced (CA-US) HIV RNA in total CD4+ T-cells from blood at day 14. The study is registered at ClinicalTrials.gov (NCT01365065). Vorinostat was safe and well tolerated and there were no dose modifications or study drug discontinuations. CA-US HIV RNA in blood increased significantly in 18/20 patients (90%) with a median fold change from baseline to peak value of 7.4 (IQR 3.4, 9.1). CA-US RNA was significantly elevated 8 hours post drug and remained elevated 70 days after last dose. Significant early changes in expression of genes associated with chromatin remodeling and activation of HIV transcription correlated with the magnitude of increased CA-US HIV RNA. There were no statistically significant changes in plasma HIV RNA, concentration of HIV DNA, integrated DNA, inducible virus in CD4+ T-cells or markers of T-cell activation. Vorinostat induced a significant and sustained increase in HIV transcription from latency in the majority of HIV-infected patients. However, additional interventions will be needed to efficiently induce virus production and ultimately eliminate latently infected cells.</p><p>Trial Registration</p><p>ClinicalTrials.gov <a href="http://clinicaltrials.gov/ct2/show/NCT01365065" target="_blank">NCT01365065</a></p></div

Changes in gene expression over the duration of study with most early changes occurring in T-cells.

<p>(A) ANOVA (F-test) heatmap of top 50 differentially expressed genes (DEGs) from matched donor supervised analysis (n = 9) comparing gene expression one, 14 and 84 days following the initial dose of vorinostat. Gene Expression was adjusted for baseline expression and represented as a gene-wise standardized expression (Z-score), with p-values<0.05. (B) Checkerboard map of differentially expressed genes 84 days after the initial dose of vorinostat (70 days post cessation of drug) compared to baseline showing the top 10 enriched pathways using gene subset enrichment analysis (GSEA) on the y-axis and leading edge analysis (gene members contributing most to enrichment) plotted along the x-axis. Scale represents log₂ fold change where red corresponds to up- and blue down-regulated genes respectively. (C) Pathway heatmap illustrates enrichment of gene expression in PBMC subsets at different timepoints compared to baseline. Red and blue represent up and down regulated expression of gene subsets respectively. (D) Checkerboard map of DEG at each timepoint compared to baseline. The cell subsets (modules) are plotted on the y-axis and gene members contributing to enrichment plotted on the x-axis. Scale represents log₂ fold change. Red and blue boxes represent up and down gene regulation respectively. mDC = myeloid cells; pDC = plasmacytoid dendritic cells; NK = natural killer cells.</p