CROI 2015 Program and Abstracts

Abstract Listing

Poster Abstracts

398 The Inducible HIV-1 Reservoir Predicted by Combinations of pre- and on-ART Parameters Anthony R. Cillo ; Michele Sobolowski; Elizabeth Fyne; Dianna Koontz; Feiyu Hong; JohnW. Mellors University of Pittsburgh, Pittsburgh, PA, US

Background: Antiretroviral therapy (ART) suppresses HIV-1 replication, but an inducible viral reservoir persists in resting CD4+ T (rCD4) cells. We have found that the amount of inducible HIV-1 RNA following ex vivo activation of purified rCD4 cells varies 1000-fold across donors. Here, we sought to identify the reasons for this wide variation in inducible HIV-1. Methods: We studied 10 consecutive HIV-1 infected subjects on suppressive ART with HIV-1 RNA in plasma <50 cps/mL for ≥ 1.4 years (median: 11 years). Plasma and PBMC were collected and rCD4 cells were purified by negative selection. rCD4 cells were treated for 7 days with anti-CD3/CD28 coated beads and the amount of virus produced was quantified in culture supernatants by qPCR for HIV-1 RNA. We evaluated 9 continuous variables for potential relationships with the amount of inducible HIV-1. Correlations between continuous variables and the inducible reservoir were evaluated by Spearman’s correlation. A principle component analysis (PCA) and regression (PCR) were performed using the same 9 variables to identify qualities associated with the amount of inducible HIV-1. Results: Table 1 shows the 9 variables measured along with the amount of induced HIV-1 per million rCD4 cells. No individual variable correlated significantly with the amount of inducible HIV-1. PCA/PCR was performed to determine the proportion of variation in inducible HIV-1 that could be explained by linear combinations of the 9 variables analyzed. The first 3 dimensions of the PCA explained >80% of the variance in inducible HIV-1. Inducible HIV-1 was positively associated with combinations of pre-ART plasma HIV-1 RNA, residual plasma viremia, and cellular HIV-1 RNA and DNA in PBMC; and inversely associated with CD4 counts at nadir and on suppressive ART.

Conclusions: 80% of the inter-patient variation in the amount of inducible HIV-1 from resting CD4+T-cells was explained by 3 principle components that included pre-ART plasma HIV-1 RNA, residual plasma viremia on ART, cell-associated HIV-1 DNA and RNA levels, and CD4 cell counts pre- and post-ART. This finding supports a model in which no one variable predicts the size of the latent inducible reservoir, but combinations of immunologic and virologic measures explain much of the observed variation in inducible HIV-1. 399 Effects of Antineoplastic Chemotherapy on Dynamics of HIV Population Genetics In Vivo Sarah A. Watters 1 ;Wei Shao 1 ; Kieron Dunleavy 3 ; Margaret Shovlin 3 ; Mark N. Polizzotto 3 ;Thomas S. Uldrick 3 ; RobertYarchoan 3 ;WyndhamWilson 3 ; Frank Maldarelli 1 1 National Cancer Institute (NCI), Frederick, MD, US; 2 National Cancer Institute (NCI), Frederick, MD, US; 3 National Cancer Institute (NCI), Bethesda, MD, US; 4 National Cancer Institute (NCI), Bethesda, MD, US; 5 National Cancer Institute (NCI), Bethesda, MD, US; 6 National Cancer Institute (NCI), Bethesda, MD, US Background: HIV-1 infection is controlled, but not cured, by combination antiretroviral therapy (cART). Mechanisms of persistence are not well understood although recently a number of groups identified expanded clones of HIV infected cells with proviruses integrated in genes involved in growth promotion. Antineoplastic chemotherapy (CTX) includes agents that target proliferating cells and may therefore have an effect on HIV infected cells. Previously, no long term effects of CTX on levels of total cell associated HIV DNA were detected (Cillo et al., 2013); HIV infects diverse CD4 subsets and differential effects of CTX on structure of HIV populations may occur. We investigated the effects of chemotherapeutic agents on HIV populations in infected individuals undergoing CTX. Methods: HIV-1 infected patients (N=10) undergoing CTX were identified, and samples were obtained from patients with B cell lymphoma treated with EPOCH-R in the absence of cART (N=6), and from patients with Kaposi’s Sarcoma undergoing cART treated with either Paclitaxel or Doxorubicin (N=4). Samples were obtained prior to CTX, during CTX (cycles 1-6) and following CTX completion. HIV single genome sequences (SGS) were obtained, aligned (CLUSTALW), and subjected to phylogenetic and compartmentalization analyses (Simmonds AI, Slatkin-Maddison, and Hudson Population Subdivision tests). Hypermutants and drug resistance mutations were identified using Los Alamos and Stanford Drug Resistance Databases, respectively. Results: In patients on a regimen of EPOCH-R for B cell lymphoma, in the absence of cART, populations of identical HIV sequences appeared in plasma during chemotherapy with evidence of clonal populations in 2/6 and population subdivision in 1/6 patients. In patients undergoing cART and receiving single agent CTX, no clonal sequences were detected in plasma; clonal populations were detected prior to therapy in cell associated HIV DNA in 4/4 patients on single agent CTX which persisted with no evidence of compartmentalization or population subdivision. No significant change in hypermutant frequency was detected prior to and following therapy in either study. Conclusions: EPOCH-R during untreated HIV infection resulted in HIV population changes in some patients, suggesting effects of chemotherapy in HIV infected cells. In contrast, single agent chemotherapy had minimal detectable effect on HIV populations.

Poster Abstracts

289

CROI 2015