CROI 2017 Abstract e-Book

Abstract eBook

Poster and Themed Discussion Abstracts

weeks of ART, during IRIS; and after long term ART. Sequences were aligned, genetic diversity determined (percent average pairwise difference; APD) and phylogenetic analysis performed. We defined clones as identical APOBEC-hypermutated sequences (HM clones) using Hypermut 2.0. Patient characteristics are in Table 1. Results: We found no statistically significant difference in viremia after long-term ART between patient groups. IRIS patients had higher levels of CA gag DNA and lower levels of gag RNA than those without IRIS after long-term ART (Mann-Whitney; p=0.04 and p=0.045 respectively). HIV genetic diversity was substantial and comparable in patients pre- and at 2-8 weeks of ART; p>0.05. In contrast, after long term ART, diversity was higher in TB-IRIS patients compared with those without TB or IRIS (median APD [IQR] = 2.3 [1.7, 2.8] and 0.8 [0.3; 1.3] respectively; Mann-Whitney; p=0.03). We detected more HM clones in TB infected patients and an association between TB infection and the presence of HM clones (Fisher exact p=0.03). Conclusion: Patients with TB-IRIS had a higher frequency of HIV infected cells, higher HIV genetic diversity and more HM clones after long term ART, suggesting IRIS events may permanently alter the HIV reservoir. Our data also suggest a relationship between clonal expansion and baseline TB and a shift to a more diverse proviral population after long term ART in TB-IRIS patients.

288 CCR6+ RECTAL CD4+ T-CELLS ARE A SIGNIFICANT RESERVOIR ON ART Jenny L. Anderson 1 , Gabriela Khoury 1 , Rémi Fromentin 2 , Nicolas Chomont 2 , Ma Somsouk 4 , Wendy Hartogensis 3 , Peter Bacchetti 3 , Paul Cameron 1 , Steven G. Deeks 3 , Sharon R. Lewin 1 1 Univ of Melbourne, Melbourne, Australia, 2 Univ de Montréal, Montréal, Canada, 3 Univ of California San Francisco, San Francisco, CA, USA Background: In HIV-infected individuals on antiretroviral therapy (ART), HIV integrated DNA is enriched in circulating central memory CD4+ T-cells expressing CCR6 and CXCR3. As these chemokine receptors (CKR) enable homing of CD4+ T-cells to tissue, we examined if expression of CKR and their chemokine ligands influenced HIV persistence in rectal and lymph node (LN) tissue in individuals on ART. Methods: Blood (n=48), rectal (n=19) and inguinal LN (n=8) biopsies were collected from individuals on suppressive ART for ≥3 years. HIV integrated DNA and unspliced RNA (US-RNA) were quantified by PCR in total CD4+ T-cells sorted from each site. CKR expression was measured via flow cytometry. Chemokine protein in plasma was measured by Luminex and chemokine mRNA in tissue measured by RT-qPCR. Relationships between HIV persistence and expression of CKR or chemokines were assessed via negative binomial regression. Results: CD4+ T-cells from rectum harboured 3.9 fold and 4.6 fold greater HIV integrated DNA and US-RNA respectively than blood (p<0.0001 for both), and 2.4 fold greater integrated DNA than LN (p=0.014). The CCL20 ligand for CCR6 was highly enriched in rectum compared to LN (12.7 fold difference). CCR6+CXCR3+memory CD4+ T-cells were also markedly enriched in rectum compared to blood or LN (69.8%, 21.6% and 12.4% respectively, Kruskall Wallis p<0.0001). In rectum, HIV integrated DNA and US-RNA were positively associated with the frequency of CCR6+CXCR3- memory CD4+ T-cells (p=0.028 and p=0.027 respectively) but inversely associated with CCR6+CXCR3+ T-cells (p=0.025 and p=0.030 respectively). In contrast, in LN, there was no association between integrated HIV DNA and the frequency of cells expressing CCR6 or CXCR3 while there was a weak inverse association between US-RNA and the frequency of CCR6+CXCR3- T-cells (p=0.046). Conclusion: HIV-infected individuals on ART have a high frequency of CCR6+CXCR3+ CD4+ T-cells in rectum, a positive correlation between HIV persistence and the frequency of CCR6+CXCR3- CD4+ T-cells, and high expression of CCL20 at this site. Targeting the CCR6-CCL20 axis should be considered as a novel strategy to eliminate HIV persistence. 289 Background: We recently demonstrated that Lymph node (LN) PD-1+/T follicular helper (Tfh) cells from anti-retroviral therapy (ART) treated HIV-infected individuals were enriched in cells containing replication competent virus. However, the distribution of cells containing inducible replication competent virus has been only partially elucidated in blood memory CD4 T-cell populations including the Tfh cell counterpart circulating in blood (cTfh). Methods: We have investigated the distribution of 1) total HIV-1-infected cells by Alu PCR and 2) cells containing replication competent HIV using virus outgrowth assay (VOA) within blood memory CD4 T-cell populations defined by chemokine receptor expression i.e CXCR3+CXCR5- (Th1), CXCR3-CXCR5+ (cTfh), CXCR3+CXCR5+ (Th1 cTfh), CCR4+CCR6- (Th2), and CCR4+CCR6+ (Th17) cells in ART treated (1.5-8 years) aviremic (<20 HIV RNA copies/ml) individuals (N=11). Results: No significant differences in the frequency of integrated HIV DNA in the different memory CD4 T-cell populations were found (P>0.05). However, blood Th1 cells were significantly enriched in cells containing replication competent virus as compared to any other blood CD4 T-cell population (P<0.05). The mean frequency of Th1 cells containing inducible replication competent virus was about 9 cells per million as assessed by RNA-Unit Per Million. Blood Th1 cells were also the largest contributor (42%) to the total pool of blood HIV-infected cells containing replication competent virus in the cohort. Interestingly, the fraction of HIV provirus induced by VOA was higher in Th1 cells as compared to any other blood CD4 T-cell sub-populations, suggesting that Th1 cells contained either more intact or more inducible provirus. Of note, blood CD4 T-cell populations were not significantly different in terms of 1) level of activation as assessed by HLA-DR or Ki-67 expression, 2) CCR5 and CXCR4 HIV co-receptor expression and 3) SAMHD1 HIV restriction factor expression (P>0.05). However, both Th1 and cTfh cells were significantly enriched in PD-1 expressing cells as compared to Th2 and Th17 (46% and 42%, respectively) (P<0.05), but only the levels of HIV RNA of Th1 VOA culture supernatants directly correlated with the frequency of PD-1 expression on Th1 cells (P<0.05). Conclusion: Taken together, these results indicate that blood Th1 cells represent the major blood compartment containing inducible replication competent virus in treated aviremic HIV-infected individuals. BLOOD CXCR3+ CD4 T CELLS ARE ENRICHED IN INDUCIBLE REPLICATION-COMPETENT HIV Riddhima Banga , Francesco Procopio, Matthias Cavassini, Giuseppe Pantaleo, Matthieu Perreau Lausanne Univ Hosp, Lausanne, Switzerland

Poster and Themed Discussion Abstracts

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