CROI 2018 Abstract eBook

Abstract eBook

Poster Abstracts

363 PERSISTENCE OF CD4+PD-1HIGH T CELLS DESPITE LONG-TERM SUPPRESSIVE ART

Background: HIV post-treatment controllers (PTCs) represent a natural model of sustained HIV remission, but these individuals are rare and little is known about their viral reservoir. We performed near-full length proviral sequencing to assess the proviral reservoir landscape of a cohort of PTCs and post-treatment non-controllers (NCs). The results were also used to assess the relationship between different proviral species, levels of intracellular HIV RNA expression and host immune responses. Methods: PBMCs were obtained from the pre-treatment interruption (on-ART) time point for 10 PTCs (controlled for ≥24 weeks) and 15 NCs identified through ACTG. Near-full length proviral sequencing was performed by Illumina next- generation single-genome sequencing (NG-SGS). Unspliced CA-RNA levels were quantified by qPCR. T and NK cell phenotypes were assessed by flow cytometry, and T cell intracellular cytokine staining was performed on PBMCs stimulated with an HIV gag peptide pool. Results: We obtained a total of 1193 proviral genomes. PTCs had approximately 6-fold lower levels of total proviral genomes (TPG, PTCs vs. NCs: median 1.9 vs. 11.2 copies/10 6 PBMCs, P<0.001) and intact proviral genomes (IPG, 0.1 vs. 0.6 copies/10 6 PBMCs, P=0.01). 80% of NCs vs. 0% of PTCs had TPG <5 copies/10 6 PBMCs (P<0.001). There were no significant differences between PTCs and NCs in the percent of proviruses that were intact, harboring deletions, or identical sequences detected more than once (i.e., clonally expanded). Amongst all participants, a median 97% of proviral genomes were defective, most of which harbored large deletions. CA-RNA correlated with levels of defective proviral genomes (DPG, Spearman r =0.51, P=0.02), but not with levels of IPG. Higher CD38+ NK cell percentages correlated with lower levels of DPG ( r =-0.48, P=0.02), as were higher levels of HIV-specific CD4+ cells expressing IFN-γ ( r =- 0.59, P=0.01) and CD8+ cells expressing CD107 ( r =-0.56, P=0.02). Conclusion: Prior to treatment interruption, the median total proviral genomes in PTCs was 6-fold lower than in NCs, but the proportions of intact, defective and clonally expanded viral genomes were similar in both groups. The association of defective proviral genomes with levels of CA-RNA, NK activation, and HIV-specific T cell activity support the concept that defective HIV genomes lead to viral antigen production and interact with both the innate and adaptive immune responses.

Bernard J. Macatangay 1 , Rajesh T. Gandhi 2 , Deborah McMahon 1 , Christina Lalama 3 , Ronald Bosch 3 , Joshua C. Cyktor 1 , Christopher Hensel 4 , Evelyn Hogg 5 , Luann Borowski 1 , Joseph J. Eron 6 , John W. Mellors 1 , Charles Rinaldo 1 1 University of Pittsburgh, Pittsburgh, PA, USA, 2 Massachusetts General Hospital, Boston, MA, USA, 3 Harvard University, Cambridge, MA, USA, 4 Frontier Science & Technology Research Foundation, Inc, Amherst, NY, USA, 5 Social &Scientific Systems, Silver Spring, MD, USA, 6 University of North Carolina Chapel Hill, Chapel Hill, NC, USA Background: CD4+ T cells expressing the checkpoint inhibitor PD-1 may be enriched for HIV infection but the impact of ART on their frequency and association with measures of HIV persistence are uncertain. Methods: We evaluated longitudinal changes in T cell PD-1 expression and their correlation with HIV persistence and immune activation in ACTG A5321 participants who initiated ART during chronic infection and had well- documented sustained viremia suppression. We gated on two T cell populations: positive for PD-1 (PD1+) vs high expression (PD1hi) since the latter subset is reported to have a different functional profile. Results: Among the 97 participants, there were significant but modest decreases to 1 year of ART in %PD1+ (median 49.5% to 46%) and %PD1hi (median 0.7% to 0.4%) CD4+ T cells (p<0.001; signed rank); the relative reduction in CD4+PD1hi T cells was substantially greater than CD4+PD1+ T cells (median 43% vs 9%; p=0.01). %CD4+PD1+ T cells continued to decrease to year 4 and to 6-15 years on-ART while %CD4+PD1hi T cells only declined to year 4. Pre-ART %CD4+/CD8+PD1+ correlated strongly with frequencies on-ART (Spearman r=0.92-0.95), while correlations for PD1hi expression were not as strong (r=0.28-0.52). %CD4+PD1hi levels positively correlated with cell- associated HIV-1 DNA pre-ART (r=0.22) and at 1 (r=0.25) and 4 years (r=0.24) on-ART, but %CD4+PD1+ levels after ART initiation did not. Residual viremia, measured by single copy assay, ≥4 years on-ART did not correlate with PD1+/ PD1hi populations. Similarly, no correlations were observed with cell-associated HIV-1 RNA. %CD4+PD1hi consistently correlated with CD4+ T cell activation (%HLA-DR+CD38+) at years 1 (r=0.40; p<0.001) and 4 (r=0.43; p<0.001) on-ART but not pre-ART. %CD8+PD1hi strongly correlated with %CD4+PD1hi at all timepoints (r=0.80-0.92) but did not consistently correlate with HIV persistence measures or T cell activation. %CD4+PD1+ did not correlate with T cell activation at any timepoint. Conclusion: PD-1 expression on CD4+ or CD8+ T cells on-ART is most strongly associated with pre-ART expression indicating long-lasting effects despite HIV-1 suppression. Among T cells expressing PD-1, the CD4+PD1hi subset stabilized after initially declining on ART and was positively associated with HIV DNA levels and CD4+ T cell activation, whereas other CD4+PD1+ T-cells were not. Distinguishing CD4+ T cell subsets by levels of PD-1 expression appears to be important for targeting the HIV reservoir.

Poster Abstracts

364 PROVIRAL LANDSCAPE IN HIV-1 POST-TREATMENT CONTROLLERS AND NON-CONTROLLERS Radwa Sharaf 1 , Guinevere Q. Lee 2 , Xiaoming Sun 2 , Evgenia Aga 3 , Ronald Bosch 3 , Rajesh T. Gandhi 4 , Jeffrey Jacobson 5 , Edward P. Acosta 6 , Daniel R. Kuritzkes 1 , Michael M. Lederman 7 , Xu G. Yu 2 , Mathias Lichterfeld 2 , Jonathan Z. Li 1 1 Brigham and Women’s Hospital, Boston, MA, USA, 2 Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA, 3 Harvard University, Cambridge, MA, USA, 4 Massachusetts General Hospital, Boston, MA, USA, 5 Temple University, Philadelphia, PA, USA, 6 University of Alabama at Birmingham, Birmingham, AL, USA, 7 Case Western Reserve University, Cleveland, OH, USA

CROI 2018 127