CROI 2020 Abstract eBook

Abstract eBook

Poster Abstracts

we undertook a thorough analysis of DN T-cells in the lungs vs blood of ART- treated HIV-infected individuals. Methods: 17 long-term ART-suppressed adults (median 9 years) and 8 uninfected controls, both without active respiratory symptoms, were recruited. Bronchoscopies were performed to obtain bronchoalveolar lavage (BAL) fluid, and matched blood was collected. T-cell subsets and HIV p24 were characterized by flow cytometry and HIV-DNA levels were measured by ultrasensitive PCR. To examine DN T-cell dynamics in acute vs chronic infection lung, spleen and blood specimens from R5-HIV infected BLT humanized mice (hu-mice) were assessed. Results: FACS-sorted DN T-cells from BAL harbored HIV-DNA in ART+ adults although HIV-DNA levels were lower in DN vs lung CD4 T-cells. Both HIV+ and HIV- adults had greater CD3+CD4-CD8α-CD8β- cell frequencies in BAL vs blood, while CD3+CD4-CD8-TCRαβ-TCRγδ- cells were only enriched in BAL from HIV+ individuals. In contrast to blood, pulmonary DN T-cells in both HIV+ and HIV- groups displayed mostly an effector memory phenotype (CD45RA-CD28+). However, HIV+ individuals had more activated (HLA-DR+) DN cells and fewer senescent (CD28-CD57+) and recent thymic migrant (CD31+) lung DN cells. No changes were noted in CXCR3+ (lung epithelium homing) DN T-cells within lungs vs blood. Similar to humans, CD3+CD4-CD8α-CD8β- DN T-cells were enriched in BAL vs blood of HIV+ and HIV- hu-mice. Importantly, p24+ DN T-cell frequencies within the lungs were consistently higher than in blood and spleen in both acute and chronic HIV infection of hu-mice. Like in humans, fewer lung DN T-cells in hu-mice had a recent thymic migrant phenotype, suggesting their local expansion within the lungs due to HIV infection. Conclusion: Long-term ART-suppressed adults have higher frequencies of DN T-cells in lungs vs blood and exhibit HIV-DNA persistence within their lung DN T-cells. In hu-mice, HIV is seeded within the lung DN T-cells during acute infection. As in HIV infection lung DN T-cells are activated effector memory cells expressing reduced senescence and thymic migration phenotypes vs blood, viral reservoirs are likely to be more active in lungs despite long-term ART. 333 EFFECT OF TAMOXIFEN ON VORINOSTAT-INDUCED HIV RNA EXPRESSION IN WOMEN ON ART (A5366) Eileen P. Scully 1 , Athe Tsibris 2 , Evgenia Aga 3 , Qing Ma 4 , Kate Starr 5 , Kathleen E. Squires 6 , Steven G. Deeks 7 , Elizabeth Connick 8 , Monica Gandhi 7 , Ronald Bosch 3 , Nancie Archin 9 , Jonathan Karn 10 , Daniel R. Kuritzkes 2 , Rajesh T. Gandhi 11 , for the ACTG A5366 Study Team 1 Johns Hopkins University, Baltimore, MD, USA, 2 Brigham and Women's Hospital, Boston, MA, USA, 3 Harvard T.H. Chan School of Public Health, Boston, MA, USA, 4 University of Rochester, Rochester, NY, USA, 5 The Ohio State University, Columbus, OH, USA, 6 Merck & Co, Inc, Upper Gwynedd, PA, USA, 7 University of California San Francisco, San Francisco, CA, USA, 8 University of Arizona, Tucson, AZ, USA, 9 University of North Carolina at Chapel Hill, Chapel Hill, NC, USA, 10 Case Western Reserve University, Cleveland, OH, USA, 11 Massachusetts General Hospital, Boston, MA, USA Background: HIV reservoirs differ between men and women but few women have been enrolled in HIV cure trials to date. In vitro and ex vivo data have identified a suppressive role for the estrogen receptor in HIV transcriptional control. ACTG A5366 investigated whether the selective estrogen receptor modulator tamoxifen enhances HIV transcription in vivo after vorinostat exposure. Methods: Postmenopausal women with HIV suppression for >1 yr and continuous ART for >=2 yrs were randomized 2:1 to 5 wks of tamoxifen (ArmA) vs observation (ArmB); both groups then received 2 doses of 400mg of vorinostat separated by 72 hrs. Primary outcomes were safety in all treated women and change in HIV RNA expression from baseline to 5 hrs after second vorinostat dose in those receiving full study treatment (efficacy group). Total HIV DNA and unspliced cell-associated RNA(caRNA) were measured in 5x10 6 CD4 T cells by qPCR, and spliced HIV envelope transcripts were measured in 106 resting memory CD4 cells by EDITS assay. Single copy assay(SCA) of plasma viremia and histone acetylation by ELISA were measured. Arms were compared by t-tests. Results: 31 women enrolled in 3 months; median age 57, 58% African American, median CD4 count 688 cells/mm 3 . No >=Grade 3 adverse events related to study drugs were seen. 27 women comprised the efficacy group (19 ArmA, 8 ArmB). There was no difference between the groups in the change in HIV expression by caRNA (mean fold change: ArmA 1.2, ArmB 1.5, p=0.6) or in EDITS (mean fold change ArmA 1.5, ArmB 4.3, p=0.12). Following vorinostat, 18 participants had increased histone acetylation; in these women, HIV

expression by EDITS also increased (mean fold increase: Overall 2.8; ArmA 1.7; ArmB 7.4; Table 1). There were no changes in HIV DNA or SCA. Targeted plasma concentrations of tamoxifen and vorinostat were achieved. Conclusion: In post-menopausal women receiving vorinostat, ESR1 antagonismwith tamoxifen was not associated with a significant change in the magnitude of HIV RNA induction by qPCR or EDITS. Induction of HIV RNA after vorinostat by the EDITS assay was primarily seen in women with increases in histone acetylation which was only observed in 67% of trial participants; this may have limited the ability to detect an effect of tamoxifen. This clinical trial, the first to study HIV latency reversal exclusively in women, was rapidly enrolled and completed, supporting the feasibility of future efforts to investigate sex- specific features of the HIV reservoir.

334 EFFECTS OF IMMUNE CHECKPOINT THERAPY ON LATENT HIV IN PEOPLE WITH HIV AND MALIGNANCY Jillian S. Lau 1 , James McMahon 1 , Ajantha Solomon 2 , Chris Y. Chiu 2 , Celine Gubser 2 , Jennifer M. Zerbato 2 , Jill Garlick 1 , Ashanti Dantanarayana 2 , Socheata Chea 2 , Surekha Tennakoon 2 , Vincent Morcilla 3 , Sarah Palmer 3 , Sharon R. Lewin 2 , Thomas A. Rasmussen 2 1 The Alfred Hospital, Melbourne, VIC, Australia, 2 Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia, 3 The Westmead Institute for Medical Research, Westmead, NSW, Australia Background: Immune checkpoint blockade (ICB) is highly effective for the management of some malignancies and can potentially perturb HIV persistence in people living with HIV (PLWH) on antiretroviral therapy (ART) by enhancing HIV-specific CD8+ T cells and/or reversing HIV latency. We established a prospective cohort of PLWH on ART with malignancy who received any ICB and quantified immunological and virological changes in three participants. Methods: Blood was collected prior to and following the first 4 cycles of ICB at day-1,+1 and +7. We quantified cell associated (CA) unspliced (US) RNA and HIV DNA from peripheral blood CD4+ T cells, frequency of cells with inducible multiply spliced (MS) HIV RNA by the Tat/rev Induced Limiting Dilution Assay (TILDA) and HIV RNA in plasma by single copy assay (SCA). Gag specific immune responses were measured by intracellular cytokine staining (ICS) for IFN-γ, TNF-α, and CD107a in T-cell subsets defined by expression of CD45RA and CCR7. Results: Participant (P) 1 received avelumab (anti-PD-L1) 2 weekly for chest wall Merkel cell carcinoma. P2 and P3 received ipilimumab (anti-CTLA4) and nivolumab (anti-PD1) 3 weekly for metastatic melanoma. P1 demonstrated partial response to ICB, before relapse and progression of disease. P2 had disease progression on ICB and died before study completion. P3 responded to ICB and remains on maintenance anti-PD-1. An increase in CA-US RNA following each infusion was noted in all 3 participants (Fig1 A,B). There was an increase in the mean fold change in CA-US RNA from cycle 1 to 4 of 1.3, 3.1, 6.8 and 8.6 respectively. No consistent changes in HIV DNA were noted in any participants. P3 had an increase in plasma viremia from a baseline of 4 c/mL to 16 and 8 c/ml following cycle 2 and 3 respectively, and a 33% reduction in inducible MS RNA as measured by TILDA. There were no changes in plasma viremia or inducible MS RNA in P1 or P2. With respect to gag-specific ICS, P2 demonstrated a striking increase in the frequency of central and effector memory CD8+ T cells producing IFN-γ, TNF-α, and CD107a (Fig1C-E), which were not demonstrated in P1 and P3. Conclusion: Increases in HIV transcription were observed on ART in all three participants following each cycle of either anti-PD-L1 or anti-PD-1 + anti- CTLA-4, with variable effects on plasma viremia, TILDA and ICS. Our results highlight that ICB can perturb HIV latency and increase HIV-specific immune responses but with significant variation between individuals.

Poster Abstracts

CROI 2020 115