Plasmacytoid dendritic cell and functional HIV Gag p55-specific T cells before treatment interruption can inform set-point plasma HIV viral load after treatment interruption in chronically suppressed HIV-1(+) patients.

The identification of immune correlates of HIV control is important for the design of immunotherapies that could support cure or antiretroviral therapy (ART) intensification-related strategies. ART interruptions may facilitate this task through exposure of an ART partially reconstituted immune system to endogenous virus. We investigated the relationship between set-point plasma HIV viral load (VL) during an ART interruption and innate/adaptive parameters before or after interruption. Dendritic cell (DC), natural killer (NK) cell and HIV Gag p55-specific T-cell functional responses were measured in paired cryopreserved peripheral blood mononuclear cells obtained at the beginning (on ART) and at set-point of an open-ended interruption from 31 ART-suppressed chronically HIV-1(+) patients. Spearman correlation and linear regression modeling were used. Frequencies of plasmacytoid DC (pDC), and HIV Gag p55-specific CD3(+)  CD4(-)  perforin(+)  IFN-γ(+) cells at the beginning of interruption associated negatively with set-point plasma VL. Inclusion of both variables with interaction into a model resulted in the best fit (adjusted R(2)  = 0·6874). Frequencies of pDC or HIV Gag p55-specific CD3(+)  CD4(-)  CSFE(lo)  CD107a(+) cells at set-point associated negatively with set-point plasma VL. The dual contribution of pDC and anti-HIV T-cell responses to viral control, supported by our models, suggests that these variables may serve as immune correlates of viral control and could be integrated in cure or ART-intensification strategies.

Community engagement group model in basic and biomedical research: lessons learned from the BEAT-HIV Delaney Collaboratory towards an HIV-1 cure.

INTRODUCTION: Achieving effective community engagement has been an objective of U.S. National Institutes of Health-funded HIV research efforts, including participation of persons with HIV. Community Advisory Boards (CABs) have remained the predominant model for community engagement since their creation in 1989. As HIV cure-directed research efforts have grown into larger academic-industry partnerships directing resources toward both basic and clinical research under the Martin Delaney Collaboratories (MDC), community input models have also evolved. The BEAT-HIV MDC Collaboratory, based at The Wistar Institute in Philadelphia, United States, implemented a three-part model for community engagement that has shown success in providing greater impact for community engagement across basic, biomedical, and social sciences research efforts. DISCUSSION: In this paper, we review the case study of the formation of the BEAT-HIV Community Engagement Group (CEG) model, starting with the historical partnership between The Wistar Institute as a basic research center and Philadelphia FIGHT as a not-for-profit community-based organization (CBO), and culminating with the growth of community engagement under the BEAT-HIV MDC. Second, we present the impact of a cooperative structure including a Community Advisory Board (CAB), CBO, and researchers through the BEAT-HIV CEG model, and highlight collaborative projects that demonstrate the potential strengths, challenges, and opportunities of this model. We also describe challenges and future opportunities for the use of the CEG model. CONCLUSIONS: Our CEG model integrating a CBO, CAB and scientists could help move us towards the goal of effective, equitable and ethical engagement in HIV cure-directed research. In sharing our lessons learned, challenges and growing pains, we contribute to the science of community engagement into biomedical research efforts with an emphasis on HIV cure-directed research. Our documented experience with implementing the CEG supports greater discussion and independent implementation efforts for this model to engage communities into working teams in a way we find a meaningful, ethical, and sustainable model in support of basic, clinical/biomedical, social sciences and ethics research.

HIV biomedical research groups have prioritized community support and representation as exemplified by the creation of Community Advisory Boards (CABs). Most CABs bring diverse stakeholders to advise on research objectives as part of their activities. The BEAT-HIV Delaney Collaboratory, based at The Wistar Institute in Philadelphia, is a research program created in 2016 to advance HIV cure research. To better engage communities beyond the CAB, the BEAT-HIV Delaney Collaboratory created a Community Engagement Group (CEG) model composed of three distinct components. First, the involvement of a community-based organization (CBO) introduces the historical know-how and relationship with the community. Philadelphia FIGHT fulfills the CBO role as a provider of primary care, education, advocacy, and research support for persons with HIV. Second, the BEAT-HIV CAB provides individual experiences and community input into HIV cure research and gives updates to the broader community about the status of research. Third, basic, clinical/biomedical, and social scientists implement the scientific goals of the BEAT-HIV Collaboratory. In this paper, we aimed to highlight the strengths, challenges, lessons learned, and opportunities of the BEAT-HIV CEG model. We also present examples of collaborative community engagement projects. Our paper contributes to the literature on novel community engagement approaches beyond the CAB. Based on our experience to date using the CEG, a multi-part community engagement model could help move us towards the goal of inclusive, effective, equitable, and ethical engagement in HIV cure research.

Circulating monocytes in HIV-1-infected viremic subjects exhibit an antiapoptosis gene signature and virus- and host-mediated apoptosis resistance.

Mechanisms that may allow circulating monocytes to persist as CD4 T cells diminish in HIV-1 infection have not been investigated. We have characterized steady-state gene expression signatures in circulating monocytes from HIV-infected subjects and have identified a stable antiapoptosis gene signature comprised of 38 genes associated with p53, CD40L, TNF, and MAPK signaling networks. The significance of this gene signature is indicated by our demonstration of cadmium chloride- or Fas ligand-induced apoptosis resistance in circulating monocytes in contrast to increasing apoptosis in CD4 T cells from the same infected subjects. As potential mechanisms in vivo, we show that monocyte CCR5 binding by HIV-1 virus or agonist chemokines serves as independent viral and host modulators resulting in increased monocyte apoptosis resistance in vitro. We also show evidence for concordance between circulating monocyte apoptosis-related gene expression in HIV-1 infection in vivo and available datasets following viral infection or envelope exposure in monocyte-derived macrophages in vitro. The identification of in vivo gene expression associated with monocyte resistance to apoptosis is of relevance to AIDS pathogenesis since it would contribute to: 1) maintaining viability of infection targets and long-term reservoirs of HIV-1 infection in the monocyte/macrophage populations, and 2) protecting a cell subset critical to host survival despite sustained high viral replication.

Lack of persistent drug-resistant mutations evaluated within and between treatment interruptions in chronically HIV-1-infected patients.

OBJECTIVE: To determine the effect of treatment interruptions (TI) on the evolution and persistence of drug-resistant viruses in chronically HIV-1-infected suppressed patients. METHODS: The emergence of viral resistance to combination antiretroviral therapy was monitored in 11 suppressed chronically HIV-1-infected patients undergoing from one up to four sequential TI (a total of 25 TI), by genotyping of the virus for known mutations in the genes for protease and reverse transcriptase. Resistance assays were performed at the first viral rebound > 100 copies/ml. RESULTS: All subjects achieved resuppression of HIV-1 under the same antiretroviral therapy, regardless of the number of TI. Five of eleven patients showed no development of resistance. In the remaining six patients, the following patterns of mutations associated with viral resistance were found: one mutation (K70R), which was observed in one patient during the 1st TI and persisted during follow-up; two mutations (L90M, M184V), which were observed in four patients during the 1st TI and were intermittently present or lost following extended TI, treatment reinitiation and/or during subsequent TI; and evolution of two mutations (M184V, K219E) observed in two patients. These two mutations were not present during the 1st TI and were subsequently lost following therapy reinitiation or during the next TI. CONCLUSIONS: Detection of drug resistance during TI by virus genotyping assays does not predict failure to resuppress after antiretroviral therapy reinitiation nor persistence of a resistant viral population during extended interruptions or subsequent TI.

Randomized, controlled trial of therapy interruption in chronic HIV-1 infection.

BACKGROUND: Approaches to limiting exposure to antiretroviral therapy (ART) drugs are an active area of HIV therapy research. Here we present longitudinal follow-up of a randomized, open-label, single-center study of the immune, viral, and safety outcomes of structured therapy interruptions (TIs) in patients with chronically suppressed HIV-1 infection as compared to equal follow-up of patients on continuous therapy and including a final therapy interruption in both arms. METHODS AND FINDINGS: Forty-two chronically HIV-infected patients on suppressive ART with CD4 counts higher than 400 were randomized 1:1 to either (1) three successive fixed TIs of 2, 4, and 6 wk, with intervening resumption of therapy with resuppression for 4 wk before subsequent interruption, or (2) 40 wk of continuous therapy, with a final open-ended TI in both treatment groups. Main outcome was analysis of the time to viral rebound (>5,000 copies/ml) during the open-ended TI. Secondary outcomes included study-defined safety criteria, viral resistance, therapy failure, and retention of immune reconstitution. There was no difference between the groups in time to viral rebound during the open-ended TI (continuous therapy/single TI, median [interquartile range] = 4 [1-8] wk, n = 21; repeated TI, median [interquartile range] = 5 [4-8] wk, n = 21; p = 0.36). No differences in study-related adverse events, viral set point at 12 or 20 wk of open-ended interruption, viral resistance or therapy failure, retention of CD4 T cell numbers on ART, or retention of lymphoproliferative recall antigen responses were noted between groups. Importantly, resistance detected shortly after initial viremia following the open-ended TI did not result in a lack of resuppression to less than 50 copies/ml after reinitiation of the same drug regimen. CONCLUSION: Cycles of 2- to 6-wk time-fixed TIs in patients with suppressed HIV infection failed to confer a clinically significant benefit with regard to viral suppression off ART. Also, secondary analysis showed no difference between the two strategies in terms of safety, retention of immune reconstitution, and clinical therapy failure. Based on these findings, we suggest that further clinical research on the long-term consequences of TI strategies to decrease drug exposure is warranted.

Increased metallothionein gene expression, zinc, and zinc-dependent resistance to apoptosis in circulating monocytes during HIV viremia.

Circulating monocytes exhibit an apoptotic resistance phenotype during HIV viremia in association with increased MT expression. MTs are known to play an important role in zinc metabolism and immune function. We now show, in a cross-sectional study using peripheral monocytes, that expression of MT1 isoforms E, G, H, and X is increased significantly in circulating monocyte cells from HIV+ subjects during chronic viremic episodes as compared with uninfected subjects. This increase in expression is also observed during acute viremia following interruption of suppressive ART. Circulating monocytes from HIV+ donors were also found to have elevated zinc importer gene Zip8 expression in conjunction with elevated intracellular zinc levels in contrast to CD4(+)T-lymphocytes. In vitro HIV-1 infection studies with elutriated MDM confirm a direct relation between HIV-1 infection and increased MDM MT1 (isoform G) gene expression and increased intracellular zinc levels. A direct link between elevated zinc levels and apoptosis resistance was established using a cell-permeable zinc chelator TPEN, which reversed apoptosis resistance effectively in monocytes from HIV-infected to levels comparable with uninfected controls. Taken together, increases in MT gene expression and intracellular zinc levels may contribute directly to maintenance of an immune-activated monocyte by mediating an increased resistance to apoptosis during active HIV-1 viremia.

HIV type 1 viremia on ART is positively associated with polyclonal T cell proliferation in subjects with T cell IFN-gamma secretion levels comparable to those of uninfected subjects.

We investigated the association between plasma HIV-1 RNA, immune activation, and polyclonal T cell function in viremic subjects whether on or off antiretroviral therapy (ART). The surface expression of activation/functional molecules on T cells and monocytes as well as cytokine secretion and T cell proliferation were assessed in 23 HIV-1(-) and 79 HIV-1(+)-infected subjects with different levels of viral suppression and CD4(+) T cell count >250 cells/mm(3) for >6 months. Viral replication was associated with increased T cell and monocyte activation irrespective of ART. In subjects with a detectable viral load on ART, we found a positive association with anti-CD3/CD28-induced T cell proliferation compared to patients with undetectable viral load (<400 copies/ml). No difference among groups was observed for anti-CD3/CD28-mediated IFN-gamma responses. The presence of an unexpected positive association between polyclonal T cell proliferation and viral load in subjects with levels of T cell IFN-gamma responses comparable to those of uninfected subjects is of potential relevance to an increase in T cell activation response before the loss of polyclonal cytokine secretion and proliferation observed with disease progression. This finding suggests that T cell hyperresponsiveness may play a role in the pathogenesis of immune comorbidities on ART.

Increased soluble vascular cell adhesion molecule-1 plasma levels and soluble intercellular adhesion molecule-1 during antiretroviral therapy interruption and retention of elevated soluble vascular cellular adhesion molecule-1 levels following resumption of antiretroviral therapy.

OBJECTIVE: We investigated the effect of short viremic episodes on soluble markers associated with endothelial stress and cardiovascular disease risk in chronically HIV-1-infected patients followed during continuous antiretroviral therapy, antiretroviral therapy interruption and antiretroviral therapy resumption. DESIGN AND METHODS: We assessed changes in plasma levels of von Willebrand factor, soluble vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 by enzyme-linked immunosorbent assay, as well as T-cell activation (CD8+/CD38+, CD8+/HLA-DR+ and CD3+/CD95+) by flow cytometry, in 36 chronically HIV-1-infected patients participating in a randomized study. Patients were divided into the following three groups: a, on continuous antiretroviral therapy; b, on a 6-week antiretroviral therapy interruption; or c, on antiretroviral therapy interruption extended to the achievement of viral set point. RESULTS: Although all measurements remained stable over a 40-week follow-up on antiretroviral therapy, plasma levels of soluble vascular cell adhesion molecule-1 (P < 0.0001) and soluble intercellular adhesion molecule-1 (P = 0.003) increased during treatment interruption in correlation with viral rebound and T-cell activation. No significant changes in von Willebrand factor were observed in any of the groups. After resuming antiretroviral therapy, soluble vascular cell adhesion molecule-1 levels remained elevated even after achievement of viral suppression to less than 50 copies/ml. CONCLUSION: The prompt rise in plasma soluble vascular cell adhesion molecule-1 and soluble intercellular adhesion molecule-1 upon viral rebound suggests an acute increase in endothelial stress upon treatment interruption, which may persists after viral resuppression of virus. Thus, viral replication during short-term treatment interruption may increase the overall cardiovascular risk during and beyond treatment interruption.