CROI 2017 Abstract e-Book

Abstract eBook

Poster and Themed Discussion Abstracts

227 EFFECT OF EXOGENOUS INTERFERON ALPHA ON HIV VIRAL POPULATIONS IN VIVO

Giorgio Bozzi 1 , Wei Shao 2 , Robin L. Dewar 2 , Vinay K. Pathak 1 , Belete A. Desimmie 1 , Ryan C. Burdick 1 , Sara Jones 3 , Claudia Balotta 4 , Mary E. Wright 5 , Frank Maldarelli 1 1 NCI, Frederick, MD, USA, 2 Leidos Biomed Rsr, Inc, Frederick, MD, USA, 3 Leidos Biomed Rsr, Inc, Bethesda, MD, USA, 4 Univ of Milan, Milan, Italy, 5 NIAID, Bethesda, MD, USA Background: Type I interferons (IFN) reduce HIV viremia c. 0.3 log10 copies/ml in the absence of antiretroviral therapy (Tavel et al., 2010) and have been reported to delay HIV rebound after discontinuing ART (Montaner, et al., 2013). Mechanisms of viral inhibition remain poorly characterized, but may proceed by immune or direct antiviral mechanisms through IFN-stimulated genes (ISG), such as APOBEC-induced hypermutation (HM), which is induced in some cell types. The effects of IFN alone in HIV infection have not been extensively studied. We investigated the direct effect of IFN-alpha on HIV populations, analyzing stored samples from a pre-ART randomized trial of individuals undergoing therapy with interferon. Methods: Peripheral blood lymphocytes (PBL) were obtained from a randomized study comparing the effects of therapy with IFN-alpha (1 million units sc, daily, escalating to 7.5 MIU), AZT (200 mg every 4 h), or the combination in HIV infected individuals with CD4 cells > 500 cells/µl. Samples pre/post 48 wk therapy from individuals with >1 log decrease in viremia during IFN were analyzed. HIV pro-pol single genome sequences (SGS) of c. 1200 nt were obtained from PBL-derived DNA, aligned (MEGA), and subjected to phylogenetic and population genetics analyses, including analysis to distinguish APOBEC3G (A3G) and 3F (A3F)-mediated changes (Desimmie et al., 2016). As interferon suppression of viremia was incomplete, we also investigated HIV populations in individuals in the trial treated with AZT monotherapy with comparable VL decrease. Results: We analyzed 487 HIV DNA SGS from individuals 48 weeks before and after IFN-alpha (N=4) or AZT (N=3) monotherapy. At entry participants had relatively early HIV infection (CD4 >500 cells/µl), and a mostly low diversity, with a mean percent average pairwise difference (APD) of 0.53% [0.2-1.1]. APD increased after 48 weeks, implying replication. At baseline HM represented 0-14% of intra-patient SGS. No significant HM increase, and no significant differences in the proportion of A3G- or A3F-mediated HM were detected comparing pre/post interferon or IFN/AZT (Fisher exact N.S.). Phylogenetic and population genetic analyses revealed no evidence of population shift. Conclusion: HIV populations were similar pre- and post-IFN, and HM did not accumulate in PBL in individuals undergoing IFN even with >1 log reduction in viremia. IFN suppressed but did not eliminate HIV variants, suggesting other ISG, such as BST-2, may contribute to reductions in viremia. 228 GENOME-WIDE METHYLATION IS ASSOCIATED WITH HIV-1 INFECTION AND DISEASE PROGRESSION Sara Moron-Lopez 1 , Judith Dalmau 1 , Victor Urrea 1 , Miguel Lopez 2 , Maria C. Puertas 1 , Beatriz Mothe 1 , Christian Brander 1 , Manel Esteller 2 , Maria Berdasco 2 , Javier Martinez-Picado 1 1 IrsiCaixa Inst for AIDS Rsr, Badalona, Spain, 2 Bellvitge Biomed Rsr Inst, L’Hosp de Llobregat, Spain Background: Human genetic variation −mostly in the HLA and CCR5 regions− explains 25% of the variability in HIV-1 disease progression. However, it is also known that viral infections are able to modify cellular DNA methylation patterns. Therefore, changes in the methylation of CpGs islands could modulate HIV-1 disease progression. Methods: We recruited 43 HIV-1 infected patients and 22 HIV-1 negative donors. A total of 84 samples were analyzed, obtained from: 22 Elite Controllers (EC group), 21 Viremic HIV-1-infected patients (Viremic group, median viral load at sample time point of 4.97 HIV-1 RNA copies/ml of plasma), 21 same Viremic patients after combination antiretroviral therapy initiation (cART group), and 22 HIV-1 negative donors (Uninfected group). Following DNA extraction from CD4 + T lymphocytes, DNA was bisulfite-converted and genotyped with Illumina Infinium Human Methylation450 arrays. After normalizing the data, we compared DNA methylation patterns between the different groups (EC, Viremic- cART paired, and Uninfected). Results: Our preliminary data highlighted 29 genes with differentially methylated promotor regions (DMR, difference in methylation >5%). The biological process enrichment analysis showed that most of these genes have a function related with either type I interferon signaling pathway, cytokine-mediated signaling pathway and regulation of viral process (p<10 -6 ). We selected 5 genes with several differentially methylated CGs in their promotor in Viremic and in EC. Specifically, we found that SPOCK2 was hypomethylated in Viremic compared with Uninfected individuals, cART and EC; USP18 was hypomethylated in Viremic vs. EC; MIB2 was hypomethylated in EC compared with Viremic and cART, and NSD1 and AURKC were hypermethylated in EC in comparison to Viremic and cART. These results suggest that MIB2, NSD1 and AURKC may play a role in in vivo HIV-1 control. Conclusion: Our results demonstrate that cellular DNA methylation is associated with HIV-1 infection and disease progression, specifically modifying the expression of genes with an immune- or viral regulation-related function. Therefore, the epigenetic regulation of host gene expression could partially explain the variability in HIV-1 disease progression. Further knowledge of the mechanism by which host DNA methylation modulates HIV-1 progression might guide the design of future therapies to achieve the remission of HIV-1 infection. 229 MITOCHONDRIAL HAPLOGROUP AND HLA-B MAY JOINTLY INFLUENCE HIV VIRAL LOAD AND CD4 COUNT Samuel Bailin , Mark Pilkinton, David C. Samuels, Silvana Gaudieri, Spyros Kalams, Todd Hulgan Vanderbilt Univ, Nashville, TN, USA Background: Genetic polymorphisms within the human leukocyte antigen (HLA) loci are important predictors of long-term HIV-1 progression. In particular, HLA-B27, B57, and B58 have been associated with lower viral load (VL) and stable CD4+ T-cell counts. More recently, studies have also shown that mitochondrial DNA (mtDNA) haplogroups are associated with CD4+ T-cell dynamics before and after initiation of antiretroviral therapy (ART). We hypothesized that HLA-B allele influence on VL and CD4+ T-cell count may differ between mtDNA haplogroups. Methods: Individuals with HIV-1 infection, CD4+ T-cell count >350, and a range of VL off ART were recruited from the Vanderbilt Comprehensive Care Clinic. Demographic data, CD4+ T-cell count, VL, HLA class-I-allele typing, and mtDNA genotyping by Sequenomwith haplogroup assignment by HaploGrep were utilized. CD4+ T-cell count and VL in individuals with HLA-B27, B57, and B58 were compared to those with other HLA-B alleles by Wilcoxon ranksum test, stratified by self-reported ancestry and mtDNA haplogroup. Frequencies of HLA-B27, B57, and B58 were compared across mtDNA haplogroup by Chi2 tests. Results: 126 individuals had mtDNA genotyping and haplogroup assignment (median baseline age 35 years, CD4+ T-cells 563 cells/mm3, VL 2436; 28% female and 50% self-reported African-American). Mitochondrial haplogroup was not significantly associated with VL or CD4+ T-cell differences. As expected, individuals with HLA-B27, B57, or B58 alleles (HLA-B+; N=41) had higher and lower CD4+ T-cells (p=0.009) and VL (p=0.004), respectively. Higher CD4+ T-cell count was seen among HLA-B+ with European haplogroup H (N=28; p=0.03) and tended to be higher with African L2 (N=15; p=0.08), but not with other haplogroups. VL tended to be lower in HLA-B+ with non-H mtDNA haplogroups (N=24; p=0.09). Haplogroup H also tended to include a higher frequency of HLA-B27, B57, or B58 allele carriers than non-H haplogroups (p=0.06), but no differences were found within the African ancestry lineage (L1, L2, or L3) or between African and European mtDNA ancestry. Conclusion: In this cohort of persons off ART, we observed associations between HLA-B alleles and VL and CD4+ T-cell count as previously described. Within some mtDNA haplogroups, we also observed novel differences in HLA-B frequencies, and in the influence of HLA-B alleles on VL and CD4+ T-cell count. Further studies with larger sample sizes are needed to better understand these potential genetic interactions and their implications. 230 T-CELL PHENOTYPE AND RECEPTOR DIVERSITY IN BLOOD & ADIPOSE TISSUE FROM HIV+ PERSONS John R. Koethe 1 Arion Kennedy, Wyatt J. McDonnell, Ian Setliff, Chike O. Abana, Mark Pilkinton, Cindy Hager, Spyros Kalams, Alyssa Hasty, Simon Mallal Vanderbilt Univ, Nashville, TN, USA Background: A high percentage of circulating activated and memory CD4+ and CD8+ T cells is associated with increased risk of developing diabetes in HIV-infected (HIV+) and HIV-negative persons, but the physiologic basis for this finding is unclear. In adipose tissue (AT), T cells modulate local inflammation and adipocyte insulin sensitivity; therefore, we hypothesized the distribution of T cells in peripheral blood from HIV+ persons is reflective of the distribution in AT. Methods: We recruited 10 non-diabetic HIV+ adults on long-term antiretroviral therapy with sustained virologic suppression to undergo fasting blood collection and subcutaneous abdominal AT biopsy. We measured the percentage of CD4+ and CD8+ T cells in AT and blood expressing activation (CD38, HLA-DR), exhaustion (PD-1), senescence

Poster and Themed Discussion Abstracts

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CROI 2017