CROI 2020 Abstract eBook

Abstract eBook

Poster Abstracts

integrated in non-genic/centromeric DNA suggests that these sequences were seeded during early disease stages and are among the most ancestral proviruses in a given patient. 382 TH2 CYTOKINES ARE ASSOCIATED WITH HIGHER LEVELS OF INTACT PROVIRUSES ON ART Joshua C. Cyktor 1 , Hanna Mar 2 , Gregory Laird 3 , Ronald Bosch 2 , Albine Martin 3 , Joseph J. Eron 4 , Bernard J. Macatangay 1 , Deborah McMahon 1 , Rajesh T. Gandhi 5 , John W. Mellors 1 1 University of Pittsburgh, Pittsburgh, PA, USA, 2 Harvard T.H. Chan School of Public Health, Boston, MA, USA, 3 Accelevir Diagnostics, Baltimore, MD, USA, 4 University of North Carolina at Chapel Hill, Chapel Hill, NC, USA, 5 Massachusetts General Hospital, Boston, MA, USA Background: Th2 cytokines, such as interleukin (IL)-4 and IL-13, regulate humoral immunity, promote production of neutralizing antibodies, and can suppress Th1 and Th17 responses by upregulating repressors of interferon (IFN)-γ and IL-17 transcription. Th2 cytokines could affect the persistence of HIV-1 on ART, but their effects on the HIV-1 reservoir have not been defined. Methods: Participants in AIDS Clinical Trials Group study A5321 who initiated ART during chronic HIV-1 infection with sustained virologic suppression had measurements of plasma HIV-1 RNA by single copy assay (SCA), total HIV-1 DNA and cell-associated RNA (CA-RNA) from PBMC, intact proviral DNA (IPDA) from CD4+ T cells, and plasma levels of IL-1RA, IL-4, IL-10, IL-11, IL-13, CCL-22, and TGFβ. Exploratory cross-sectional analyses assessed the relationship between these cytokines and measures of HIV-1 persistence. Results: 98 participants (21 females) were evaluated with a median (IQR) age of 46 years (37, 53) and 6.7 (4, 8) years on suppressive ART. Plasma levels of IL-4 were associated with the levels of intact proviral DNA (r=0.37, p=0.009), and the other main Th2 cytokine, IL-13, showed a trend towards a positive association with intact proviral DNA (r=0.26, p=0.07) (Table 1). There was also a trend towards an association of IL-4 levels with SCA HIV-1 RNA (r=0.2, p=0.06) but not total HIV-1 DNA (r=0.14, p=0.18) or CA-RNA (r=0.16, p=0.14). IL-1RA, IL-10, IL-11, IL-13, CCL-22, and TGFβ were not significantly associated with plasma SCA (N=95), total HIV-1 DNA (N=95), CA-RNA (N=90), or IPDA (N=48). Conclusion: The levels of Th2 cytokines IL-4 and IL-13 are associated with higher frequencies of cells containing intact proviral HIV-1 DNA but not total HIV-1 DNA, whereas other cytokines including IL-10 were not associated with intact or total HIV-1 DNA. There was a weaker association of IL-4 with residual viremia, which likely arises from cells with intact proviruses. This work demonstrates the value of measuring intact proviral HIV-1 DNA when evaluating the relationship between immune responses and the HIV-1 reservoir. While the mechanistic link between IL-4 and IL-13 levels and cells carrying intact proviruses is undefined, these findings suggest that the dampening effect of Th2 cytokines on Th1 and Th17 responses could promote persistence of the HIV-1 reservoir.

individuals on ART with non-suppressed viremia despite therapeutic drug levels and no evidence of drug resistance to the current ART regimen. Methods: Single, full-length Env genes were amplified from plasma by RT-PCR. Amplicons were sequenced, ligated into a mammalian expression vector, and expressed as a pseudovirus (PSV) from HEK293T cells. A luciferase-based assay was used to measure the neutralization sensitivity of the plasma sequence- derived PSVs against a panel of 16 monoclonal antibodies (mAbs) directed to the CD4 binding site (CD4bs; VRC01, 3BNC117, b12, LSEVh-ls), V1V2 apex (PG9, PG16, PGT145), glycan (2G12), V3-glycan (PGT-121, 10-1074, PGT-128), gp120-gp41 interface (PGT-151), the membrane-proximal external region (MPER) of gp41 (10e8, 4e10, and 2F5), and a tri-specific antibody (N6/PGDM1400x10E8) directed to the CD4bs, V1V2 apex, and MPER binding sites. Results: 40 unique Envs from 5 donors (R-09, C-03, C-02, T-13, F-07) were assessed. In general, the Envs tested were more resistant to Ab neutralization than a tier 1 (6535) or a tier 2 (TRO11) subtype B PSV (Table 1). Specifically, the Envs were more resistant to CD4bs, Gp41, and Apex mAbs but more sensitive to V3-glycan mAbs. Donor R-09 had the most neutralization resistant Env sequences: both R-09 PSVs (R-09_A8 and R-09_C2) showed resistance to the 3 Apex mAbs (PG9, PG16 and PGT145) and CD4bs mAb VRC01. Additionally, R-09_ C2 was the only PSV that was resistant to neutralization by N6/PGDM1400x10E8. Of the 16 mAbs tested, only 3BNC117 and 10e8 potently neutralized all the PSVs. Conclusion: Plasma-derived Envs from individuals with persistent viremia on ART exhibit reduced sensitivity to mAbs targeting CD4bs, Gp41, and Apex, compared to tier 1 and 2 Envs. 3BNC117 and 10e8, however, neutralized all PSVs assayed, indicating therapeutic potential for clearing persistent viremia in the individuals studied.

Poster Abstracts

384 MODELING HIV RESERVOIR DECLINE AFTER ART INITIATION AS A FUNCTION OF NK CELL FEATURES Elena Vendrame 1 , Geoffrey T. Ivison 1 , Rosemary Vergara 1 , Nancy Q. Zhao 1 , Giovanny J. Martínez-Colón 1 , R. Brad Jones 2 , Joshua C. Cyktor 3 , Hanna Mar 4 , Deborah McMahon 3 , Joseph J. Eron 5 , John W. Mellors 3 , Ronald Bosch 4 , Susan Holmes 1 , Rajesh T. Gandhi 6 , Catherine A. Blish 1 1 Stanford University, Stanford, CA, USA, 2 George Washington University, Washington, DC, USA, 3 University of Pittsburgh, Pittsburgh, PA, USA, 4 Harvard T.H. Chan School of Public Health, Boston, MA, USA, 5 University of North Carolina at Chapel Hill, Chapel Hill, NC, USA, 6 Massachusetts General Hospital, Boston, MA, USA Background: A major challenge in the development of HIV curative strategies is the formation of viral reservoirs that are not eradicated with antiretroviral therapy (ART). Understanding mechanisms that determine HIV reservoir size may inform development of effective cure approaches. As natural killer (NK) cells may contribute to control of HIV infection, we hypothesized that NK cells may affect reservoir size. Methods: To evaluate the association between NK cells and HIV reservoir, we used mass cytometry to profile NK cells from 50 people with HIV on suppressive ART in AIDS Clinical Trials Group study A5321. NK cell repertoire was assessed at time of study entry (median of 7.1 years after ART initiation) and 24 and 48 weeks later. Prior to ART initiation, one year following ART initiation, and at study entry, we assessed inflammatory markers and markers of HIV persistence (cell-associated DNA (CA-DNA), cell-associated RNA and HIV RNA by single copy assay). T cell responses to peptide pools were assessed at study entry. Results: In participants on chronic ART, the NK cell repertoire was stable as assessed by expression patterns of NK cell activation and differentiation markers at study entry, week 24, and week 48. At study entry, there was no significant correlation between on-ART NK cell diversity and any of the on-ART HIV reservoir measures. We next evaluated whether NK cell features, inflammatory markers, or T cell responses can explain the reduction in log 10 -transformed HIV

383 HIV-1 ENVELOPES FROM PERSISTENT VIREMIA ON ART SHOW REDUCED ANTIBODY SENSITIVITY Savrina Manhas 1 , Joseph P. Brooker 1 , Elias K. Halvas 1 , John W. Mellors 1 1 University of Pittsburgh, Pittsburgh, PA, USA Background: Despite adherence to ART, clinically detectible viremia (HIV RNA >20 copies/ml) persists in some individuals and arises from large, infected cell clones. The mechanisms by which these clones escape immune responses is not defined but envelope (Env) resistance to antibodies (Abs) could contribute. To test this, we assessed the Ab neutralization sensitivity of HIV-1 Envs from 5

CROI 2020 132