GITR activation ex vivo impairs CD8 T cell function in people with HIV on antiretroviral therapy.

Glucocorticoid-induced tumor necrosis factor related protein (GITR) is a co-stimulatory immune checkpoint molecule constitutively expressed on regulatory T cells (Tregs) and on activated T conventional cells (Tconv). In blood collected from PWH on suppressive ART, GITR expression was reduced in multiple activated CD4 and CD8 T cell subsets but was increased in Tregs. HIV specific CD8 T cells expressed higher levels of GITR and programmed cell death protein 1 (PD-1) compared to total CD8 T cells. Following stimulation with HIV peptides and GITR-ligand (L), we demonstrated a significant decrease in killing by HIV specific CD8 T cells and an increased exhausted profile. T cell receptor co-stimulation with GITR-L abrogated Treg suppression and induced expansion of CD4 Tconv. We conclude that GITR activation is an additional factor contributing to an impaired HIV immune response in PWH on ART and that GITR agonist antibodies should not be pursued for HIV cure strategies.

Combination Immune Checkpoint Blockade Enhances IL-2 and CD107a Production from HIV-Specific T Cells Ex Vivo in People Living with HIV on Antiretroviral Therapy.

In people with HIV (PWH) on antiretroviral therapy (ART), immune dysfunction persists, including elevated expression of immune checkpoint (IC) proteins on total and HIV-specific T cells. Reversing immune exhaustion is one strategy to enhance the elimination of HIV-infected cells that persist in PWH on ART. We aimed to evaluate whether blocking CTL-associated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1), T cell Ig domain and mucin domain 3 (TIM-3), T cell Ig and ITIM domain (TIGIT) and lymphocyte activation gene-3 (LAG-3) alone or in combination would enhance HIV-specific CD4+ and CD8+ T cell function ex vivo. Intracellular cytokine staining was performed using human PBMCs from PWH on ART (n = 11) and expression of CD107a, IFN-γ, TNF-α, and IL-2 was quantified with HIV peptides and Abs to IC. We found the following: 1) IC blockade enhanced the induction of CD107a and IL-2 but not IFN-γ and TNF-α in response to Gag and Nef peptides; 2) the induction of CD107a and IL-2 was greatest with multiple combinations of two Abs; and 3) Abs to LAG-3, CTLA-4, and TIGIT in combinations showed synergistic induction of IL-2 in HIV-specific CD8+ and CD107a and IL-2 production in HIV-specific CD4+ and CD8+ T cells. These results demonstrate that the combination of Abs to LAG-3, CTLA-4, or TIGIT can increase the frequency of cells expressing CD107a and IL-2 that associated with cytotoxicity and survival of HIV-specific CD4+ and CD8+ T cells in PWH on ART. These combinations should be further explored for an HIV cure.

Cell-Associated Human Immunodeficiency Virus (HIV) Ribonucleic Acid Has a Circadian Cycle in Males With HIV on Antiretroviral Therapy.

BACKGROUND: Circadian transcription factors that regulate cell-autonomous circadian clocks can also increase human immunodeficiency virus (HIV) transcription in vitro. We aimed to determine whether circadian variation in HIV transcription exists in people with HIV (PWH) on antiretroviral therapy (ART). METHODS: We performed a prospective observational study of male PWH on ART, sampling blood every 4 hours for 24 hours. Using quantitative polymerase chain reaction, we quantified expression of circadian-associated genes, HIV deoxyribonucleic acid (DNA), and cell-associated unspliced (CA-US) ribonucleic acid (RNA) in peripheral blood CD4+ T cells. Plasma sex hormones were quantified alongside plasma and salivary cortisol. The primary outcome was to identify temporal variations in CA-US HIV RNA using a linear mixed-effect regression framework and maximum likelihood estimation. RESULTS: Salivary and plasma cortisol, and circadian genes including Clock, Bmal1, and Per3, varied with a circadian rhythm. Cell-associated unspliced HIV RNA and the ratio of CA-US HIV RNA/DNA in CD4+ T cells also demonstrated circadian variations, with no variation in HIV DNA. Circulating estradiol was highly predictive of CA-US HIV RNA variation in vivo. CONCLUSIONS: Cell-associated unspliced HIV RNA in PWH on ART varies temporally with a circadian rhythm. These findings have implications for the design of clinical trials and biomarkers to assess HIV cure interventions.

Neurotoxicity with high-dose disulfiram and vorinostat used for HIV latency reversal.

OBJECTIVE: The aim of this study was to examine whether administering both vorinostat and disulfiram to people with HIV (PWH) on antiretroviral therapy (ART) is well tolerated and can enhance HIV latency reversal. DESIGN: Vorinostat and disulfiram can increase HIV transcription in PWH on ART. Together, these agents may lead to significant HIV latency reversal. METHODS: Virologically suppressed PWH on ART received disulfiram 2000 mg daily for 28 days and vorinostat 400 mg daily on days 8-10 and 22-24. The primary endpoint was plasma HIV RNA on day 11 relative to baseline using a single copy assay. Assessments included cell-associated unspliced RNA as a marker of latency reversal, HIV DNA in CD4+ T-cells, plasma HIV RNA, and plasma concentrations of ART, vorinostat, and disulfiram. RESULTS: The first two participants (P1 and P2) experienced grade 3 neurotoxicity leading to trial suspension. After 24 days, P1 presented with confusion, lethargy, and ataxia having stopped disulfiram and ART. Symptoms resolved by day 29. After 11 days, P2 presented with paranoia, emotional lability, lethargy, ataxia, and study drugs were ceased. Symptoms resolved by day 23. CA-US RNA increased by 1.4-fold and 1.3-fold for P1 and P2 respectively. Plasma HIV RNA was detectable from day 8 to 37 (peak 81 copies ml-1) for P2 but was not increased in P1 Antiretroviral levels were therapeutic and neuronal injury markers were elevated in P1. CONCLUSION: The combination of prolonged high-dose disulfiram and vorinostat was not safe in PWH on ART and should not be pursued despite evidence of latency reversal.

The impact of immune checkpoint therapy on the latent reservoir in HIV-infected individuals with cancer on antiretroviral therapy.

OBJECTIVE: The aim of this study was to quantify HIV-specific immunological and virological changes in people with HIV (PWH) on antiretroviral therapy (ART) with malignancy who received immune checkpoint blockade (ICB). DESIGN: An observational cohort study. METHODS: Blood samples were collected before and after four cycles of ICB in HIV-positive adults on ART. Virological assessments performed on CD4+ T cells included cell-associated unspliced HIV RNA, cell-associated HIV DNA, Tat/rev-induced limiting dilution assay (TILDA) and plasma HIV RNA using a single copy assay (SCA). Flow cytometry was used to assess the frequency of precursor exhausted T cells (Tpex) and exhausted T cells (Tex), and Gag-specific CD4+ and CD8+ T cells positive for IFN-γ, TNF-α or CD107a by intracellular cytokine staining (ICS). RESULTS: Participant (P)1 received avelumab (anti-PD-L1) for Merkel cell carcinoma. P2 and P3 received ipilimumab (anti-CTLA-4) and nivolumab (anti-PD-1) for metastatic melanoma. An increase in CA-US RNA following each infusion was noted in all three participants. There were no consistent changes in HIV DNA or the proportion of cells with inducible MS HIV RNA. P2 demonstrated a striking increase in the frequency of gag-specific central and effector memory CD8+ T cells producing IFN-γ, TNF-α and CD107a following anti-PD1 and anti-CTLA-4. The frequency of CD8+ Tpex cells pre-ICB was also highest in this participant. CONCLUSION: In three PWH with cancer on ART, we found that ICB activated latent HIV and enhanced HIV-specific T cell function but with considerable variation.

Diverse effects of interferon alpha on the establishment and reversal of HIV latency.

HIV latency is the major barrier to a cure for people living with HIV (PLWH) on antiretroviral therapy (ART) because the virus persists in long-lived non-proliferating and proliferating latently infected CD4+ T cells. Latently infected CD4+ T cells do not express viral proteins and are therefore not visible to immune mediated clearance. Therefore, identifying interventions that can reverse latency and also enhance immune mediated clearance is of high interest. Interferons (IFNs) have multiple immune enhancing effects and can inhibit HIV replication in activated CD4+ T cells. However, the effects of IFNs on the establishment and reversal of HIV latency is not understood. Using an in vitro model of latency, we demonstrated that plasmacytoid dendritic cells (pDC) inhibit the establishment of HIV latency through secretion of type I IFNα, IFNß and IFNω but not IFNε or type III IFNλ1 and IFNλ3. However, once latency was established, IFNα but no other IFNs were able to efficiently reverse latency in both an in vitro model of latency and CD4+ T cells collected from PLWH on suppressive ART. Binding of IFNα to its receptor expressed on primary CD4+ T cells did not induce activation of the canonical or non-canonical NFκB pathway but did induce phosphorylation of STAT1, 3 and 5 proteins. STAT5 has been previously demonstrated to bind to the HIV long terminal repeat and activate HIV transcription. We demonstrate diverse effects of interferons on HIV latency with type I IFNα; inhibiting the establishment of latency but also reversing HIV latency once latency is established.

Human Immunodeficiency Virus (HIV)-Infected CCR6+ Rectal CD4+ T Cells and HIV Persistence On Antiretroviral Therapy.

BACKGROUND: Identifying where human immunodeficiency virus (HIV) persists in people living with HIV and receiving antiretroviral therapy is critical to develop cure strategies. We assessed the relationship of HIV persistence to expression of chemokine receptors and their chemokines in blood (n = 48) and in rectal (n = 20) and lymph node (LN; n = 8) tissue collected from people living with HIV who were receiving suppressive antiretroviral therapy. METHODS: Cell-associated integrated HIV DNA, unspliced HIV RNA, and chemokine messenger RNA were quantified by quantitative polymerase chain reaction. Chemokine receptor expression on CD4+ T cells was determined using flow cytometry. RESULTS: Integrated HIV DNA levels in CD4+ T cells, CCR6+CXCR3+ memory CD4+ T-cell frequency, and CCL20 expression (ligand for CCR6) were highest in rectal tissue, where HIV-infected CCR6+ T cells accounted for nearly all infected cells (median, 89.7%). Conversely in LN tissue, CCR6+ T cells were infrequent, and there was a statistically significant association of cell-associated HIV DNA and RNA with CCL19, CCL21, and CXCL13 chemokines. CONCLUSIONS: HIV-infected CCR6+ CD4+ T cells accounted for the majority of infected cells in rectal tissue. The different relationships between HIV persistence and T-cell subsets and chemokines in rectal and LN tissue suggest that different tissue-specific strategies may be required to eliminate HIV persistence and that assessment of biomarkers for HIV persistence may not be generalizable between blood and other tissues.

Sex-Based Differences in Human Immunodeficiency Virus Type 1 Reservoir Activity and Residual Immune Activation.

Plasma human immunodeficiency virus type 1 (HIV-1) RNA levels in women are lower early in untreated HIV-1 infection compared with those in men, but women have higher T-cell activation and faster disease progression when adjusted for viral load. It is not known whether these sex differences persist during effective antiretroviral therapy (ART), or whether they would be relevant for the evaluation and implementation of HIV-1 cure strategies. We prospectively enrolled a cohort of reproductive-aged women and matched men on suppressive ART and measured markers of HIV-1 persistence, residual virus activity, and immune activation. The frequency of CD4+ T cells harboring HIV-1 DNA was comparable between the sexes, but there was higher cell-associated HIV-1 RNA, higher plasma HIV-1 (single copy assay), and higher T-cell activation and PD-1 expression in men compared with women. These sex-related differences in immune phenotype and HIV-1 persistence on ART have significant implications for the design and measurement of curative interventions.

Variation in cell-associated unspliced HIV RNA on antiretroviral therapy is associated with the circadian regulator brain-and-muscle-ARNT-like-1.

OBJECTIVE(S): To determine whether variation in cell-associated unspliced (CA-US) HIV RNA in HIV-infected individuals on antiretroviral therapy (ART) has a circadian basis. METHODS: Prospective observational study of HIV-infected individuals on ART. Blood was collected on three occasions and CA-US HIV RNA and mRNA of the circadian-locomotor-output-cycles-kaput (CLOCK)-associated genes quantified by real time PCR. CLOCK-associated proteins were over-expressed in a cell line stably transfected with an HIV long-terminal repeat (LTR) luciferase reporter. RESULTS: Using a mixed effects model, there was a significant increase in log-CA-US RNA at the third visit compared with the first visit (effect size of 0.619 with standard error (SE) of 0.098, P < 0.001) and an independent effect of time of blood draw (effect size 0.051 (SE 0.025), P = 0.040). The CLOCK-associated gene, brain-and-muscle-ARNT-like-1 (BMAL-1) had a significant relationship with log CA-US HIV RNA (effect size 8.508 (SE 3.777), P = 0.028) and also with time (P = 0.045). Over expression of BMAL-1 and CLOCK in a cell line stably transfected with an HIV-LTR luciferase reporter resulted in an increase in luciferase expression and this was reduced following mutation of the second E-box in the HIV-LTR. CONCLUSION: The basal level of HIV transcription on ART can vary significantly and is modulated by the circadian regulator BMAL-1, amongst other factors.

Programmed cell death-1 contributes to the establishment and maintenance of HIV-1 latency.

OBJECTIVE: In HIV-infected individuals on antiretroviral therapy (ART), latent HIV is enriched in CD4 T cells expressing immune checkpoint molecules, in particular programmed cell death-1 (PD-1). We therefore assessed the effect of blocking PD-1 on latency, both in vitro and in vivo. METHODS: HIV latency was established in vitro following coculture of resting CD4+ T cells with myeloid dendritic cells. Expression of PD-1 was quantified by flow cytometry, and latency assessed in sorted PD-1high and PD-1low/-nonproliferating CD4+ memory T cells. The role of PD-1 in the establishment of latency was determined by adding anti-PD-1 (pembrolizumab) to cocultures before and after infection. In addition, a single infusion of anti-PD-1 (nivolumab) was administered to an HIV-infected individual on ART with metastatic melanoma, and cell-associated HIV DNA and RNA, and plasma HIV RNA were quantified. RESULTS: HIV latency was significantly enriched in PD-1high compared with PD-1low/- nonproliferating, CD4 memory T cells. Sorting for an additional immune checkpoint molecule, T-cell immunoglobulin domain and mucin domain-3, in combination with PD-1, further enriched for latency. Blocking PD-1 prior to HIV infection, in vitro, resulted in a modest but significant decrease in latently infected cells in all donors (n = 6). The administration of anti-PD-1 to an HIV-infected individual on ART resulted in a significant increase in cell-associated HIV RNA in CD4 T cells, without significant changes in HIV DNA or plasma HIV RNA, consistent with reversal of HIV latency. CONCLUSION: PD-1 contributes to the establishment and maintenance of HIV latency and should be explored as a target, in combination with other immune checkpoint molecules, to reverse latency.

Human Immunodeficiency Virus Persistence and T-Cell Activation in Blood, Rectal, and Lymph Node Tissue in Human Immunodeficiency Virus-Infected Individuals Receiving Suppressive Antiretroviral Therapy.

Background: Immune activation and inflammation remain elevated in human immunodeficiency virus (HIV)-infected individuals receiving antiretroviral therapy (ART) and may contribute to HIV persistence. Methods: Using flow cytometry expression of CD38, HLA-DR and PD-1 were measured in blood (n = 48), lymph node (LN; n = 9), and rectal tissue (n = 17) from virally suppressed individuals. Total and integrated HIV DNA, 2-LTR circles, and cell-associated unspliced HIV RNA were quantified. Results: CD4+ T cells from rectal tissue had a higher frequency of integrated HIV DNA compared with blood (4.26 fold-change in DNA; 95% confidence interval [CI] = 2.61-7.00; P < .001) and LN (2.32 fold-change in DNA; 95% CI = 1.22-4.41; P = .01). In rectal tissue, there were positive associations between integrated HIV DNA with PD-1+ CD4+ T-cells (1.44 fold-change in integrated HIV DNA per 10-unit increase in PD-1+ CD4+ T cells; 95% CI = 1.01-2.05; P = .045) and CD38+HLA-DR+ CD8+ T cells (1.40 fold-change in integrated HIV DNA per 1-unit increase in CD38+HLA-DR+ CD8+ T cells; 95% CI = 1.05-1.86; P = .02). Both associations were independent of current and nadir CD4+ T-cell counts. Conclusions: During ART, rectal tissue is an important reservoir for HIV persistence with a high frequency of activated CD4+ and CD8+ T cells. PD-1 may represent a marker of HIV persistence in rectal tissue.

Broad activation of latent HIV-1 in vivo.

The 'shock and kill' approach to cure human immunodeficiency virus (HIV) includes transcriptional induction of latent HIV-1 proviruses using latency-reversing agents (LRAs) with targeted immunotherapy to purge infected cells. The administration of LRAs (panobinostat or vorinostat) to HIV-1-infected individuals on antiretroviral therapy induces a significant increase in cell-associated unspliced (CA-US) HIV-1 RNA from CD4(+) T cells. However, it is important to discern whether the increases in CA-US HIV-1 RNA are due to limited or broad activation of HIV-1 proviruses. Here we use single-genome sequencing to find that the RNA transcripts observed following LRA administration are genetically diverse, indicating activation of transcription from an extensive range of proviruses. Defective sequences are more frequently found in CA HIV-1 RNA than in HIV-1 DNA, which has implications for developing an accurate measure of HIV-1 reservoir size. Our findings provide insights into the effects of panobinostat and vorinostat as LRAs for latent HIV-1.

Understanding Factors That Modulate the Establishment of HIV Latency in Resting CD4+ T-Cells In Vitro.

Developing robust in vitro models of HIV latency is needed to better understand how latency is established, maintained and reversed. In this study, we examined the effects of donor variability, HIV titre and co-receptor usage on establishing HIV latency in vitro using two models of HIV latency. Using the CCL19 model of HIV latency, we found that in up to 50% of donors, CCL19 enhanced latent infection of resting CD4+ T-cells by CXCR4-tropic HIV in the presence of low dose IL-2. Increasing the infectious titre of CXCR4-tropic HIV increased both productive and latent infection of resting CD4+ T-cells. In a different model where myeloid dendritic cells (mDC) were co-cultured with resting CD4+ T-cells, we observed a higher frequency of latently infected cells in vitro than CCL19-treated or unstimulated CD4+ T-cells in the presence of low dose IL-2. In the DC-T-cell model, latency was established with both CCR5- and CXCR4-tropic virus but higher titres of CCR5-tropic virus was required in most donors. The establishment of latency in vitro through direct infection of resting CD4+ T-cells is significantly enhanced by CCL19 and mDC, but the efficiency is dependent on virus titre, co-receptor usage and there is significant donor variability.

Polymorphisms in the CD14 and TLR4 genes independently predict CD4+ T-cell recovery in HIV-infected individuals on antiretroviral therapy.

BACKGROUND: Chronic HIV infection leads to marked depletion of CD4 T cells in the gastrointestinal tract and increased microbial translocation measured by an increase in circulating lipopolysaccharide (LPS) levels. Here, we hypothesized that single-nucleotide polymorphisms (SNPs) in genes encoding the Toll-like receptor 4 (TLR4) and CD14, the principal receptors for LPS, were associated with CD4 T-cell recovery postantiretroviral therapy (ART). METHODS: Prospective study of predominantly white HIV-infected participants receiving suppressive ART for at least 12 months. We analysed the CD14 SNPs C-260T and the TLR4 SNPs A+896G, C+1196T. We also determined the levels of LPS and soluble CD14 in plasma samples collected pre-ART and post-ART initiation. CD4 T-cell recovery was assessed by linear mixed models. RESULTS: Following ART, individuals with a TT genotype compared with a CT or CC genotype for CD14 C-260T SNP showed higher levels of soluble CD14 (P = 0.008 and 0.003, respectively). The CC genotype for the CD14 C-260T SNP, compared with CT or TT, and the TLR4 SNP (AC/GT), compared with the homozygous genotype (AA/CC), were both independently associated with enhanced long-term CD4 T-cell recovery (>3 months; P < 0.001). CONCLUSION: Polymorphisms in CD14 and TLR4 are independently associated with long-term CD4 T-cell recovery in HIV-infected individuals post-ART.

Short-term administration of disulfiram for reversal of latent HIV infection: a phase 2 dose-escalation study.

BACKGROUND: In vitro, disulfiram activated HIV transcription in a primary T-cell model of HIV latency and in a pilot clinical study increased plasma HIV RNA in individuals with adequate drug exposure. We assessed the effect of disulfiram on HIV transcription in a dose-escalation study. METHODS: In this prospective dose-escalation study, to optimise disulfiram exposure we included adults with HIV on suppressive antiretroviral therapy, with plasma HIV RNA of less than 50 copies per mL and a CD4 cell count greater than 350 cells per µL. Participants were allocated sequentially to one of three dosing groups (500 mg, 1000 mg, and 2000 mg) and received disulfiram daily for 3 days. Only the staff who did laboratory assays were masked to group assignment. The primary endpoint was change in cell-associated unspliced HIV RNA in CD4 cells. The primary analysis method was a negative binomial regression, with the number of copies as the outcome variable and the input total RNA or plasma volume as an exposure variable, which is equivalent to modelling copies or input. We used these models to estimate changes from before disulfiram to timepoints during and after disulfiram administration. This study is registered with ClinicalTrials.gov, number NCT01944371. FINDINGS: Of 34 participants screened for eligibility at The Alfred Hospital (Melbourne, VIC, Australia), and San Francisco General Hospital (San Francisco, CA, USA), 30 people were enrolled between Sept 24, 2013, and March 31, 2014. The estimated fold increases in cell-associated unspliced HIV RNA from baseline were 1·7 (95% CI 1·3-2·2; p<0·0001) to the timepoint during disulfiram treatment and 2·1 (1·5-2·9; p<0·0001) to the timepoint after disulfiram in the 500 mg group; 1·9 (1·6-2·4; p<0·0001) and 2·5 (1·9-3·3; p<0·0001) in the 1000 mg group; and 1·6 (1·2-2·1; p=0·0026) and 2·1 (1·5-3·1; p=0·0001) in the 2000 mg group. No deaths occurred, and no serious adverse events were noted. Disulfiram was well tolerated at all doses. INTERPRETATION: Short-term administration of disulfiram resulted in increases in cell-associated unspliced HIV RNA at all doses, consistent with activating HIV latency. Disulfiram may be suited for future studies of combination and prolonged therapy to activate latent HIV. FUNDING: The Foundation for AIDS Research (amfAR); National Institute of Allergy and Infectious Diseases, National Institutes of Health; Australian National Health and Medical Research Council.

Activation of HIV transcription with short-course vorinostat in HIV-infected patients on suppressive antiretroviral therapy.

UNLABELLED: 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. TRIAL REGISTRATION: ClinicalTrials.gov NCT01365065.

No difference in the rate of change in telomere length or telomerase activity in HIV-infected patients after three years of darunavir/ritonavir with and without nucleoside analogues in the MONET trial.

OBJECTIVE: To determine whether nucleos(t)ide reverse transcriptase inhibitors (NRTI) contribute to an accelerated loss in telomere length (TL) in HIV-infected patients on antiretroviral therapy (ART). DESIGN: Substudy of randomised controlled trial. METHODS: Patients with HIV RNA <50 copies/mL on combination ART (n = 256) were randomised to darunavir/ritonavir (DRV/r) 800/100 mg once daily, either as monotherapy (n = 127) or with 2 NRTIs (n = 129) for up to 144 weeks. TL and telomerase activity was quantified on stored peripheral blood mononuclear cells (PBMC; n = 124) using quantitative real time PCR. RESULTS: Patients in the sub-study had a mean age of 44 years and had received NRTI for a mean of 6.4 years (range 1-20 years). As expected, older patients have significantly shorter TL (p = 0.006), while women had significantly longer TL (p = 0.026). There was no significant association between TL and either the duration of prior NRTI treatment (p = 0.894) or the use of a PI versus NNRTI (p = 0.107). There was no significant difference between patients who continued or ceased NRTI in the mean change/year of TL or telomerase (p = 0.580 and 0.280 respectively). CONCLUSION: Continuation versus cessation of NRTI treatment was not associated with an accelerated loss in TL or telomerase activity.

Lipopolysaccharide, immune activation, and liver abnormalities in HIV/hepatitis B virus (HBV)-coinfected individuals receiving HBV-active combination antiretroviral therapy.

We investigated the relationship between microbial translocation, immune activation, and liver disease in human immunodeficiency virus (HIV)/hepatitis B virus (HBV) coinfection. Lipopolysaccharide (LPS), soluble CD14, CXCL10, and CCL-2 levels were elevated in patients with HIV/HBV coinfection. Levels of LPS, soluble CD14, and CCL-2 declined following receipt of HBV-active combination antiretroviral therapy (cART), but the CXCL10 level remained elevated. No markers were associated with liver disease severity on liver biopsy (n = 96), but CXCL10, interleukin 6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor α, and interferon γ (IFN-γ) were all associated with elevated liver enzyme levels during receipt of HBV-active cART. Stimulation of hepatocyte cell lines in vitro with IFN-γ and LPS induced a profound synergistic increase in the production of CXCL10. LPS may contribute to liver disease via stimulating persistent production of CXCL10.