CROI 2017 Abstract e-Book

Abstract eBook

Poster and Themed Discussion Abstracts

of lipopolysaccharide (LPS), a toll-like receptor (TLR4) agonist. Purinergic receptors are inflammatory mediators that have been increasingly implicated in HIV-1 pathogenesis. These receptors signal in concert with TLR signaling. We have demonstrated that inhibition of purinergic receptors can inhibit HIV-1 fusion. Here we test whether inhibition of P2X subtypes can reduce both HIV-1 infection and pro-inflammatory cytokine production. Methods: CD4+ T cells and peripheral mononuclear blood cells were infected with fluorescent reporter HIV-1 viruses and tested for their productive infection and proinflammatory cytokine production. Infected cells were quantified by flow cytometry and supernatants were subjected to multiplex bead capture assays to detect an array of human inflammatory cytokines. The effect of P2X selective inhibitors was tested. Results: P2X inhibition was associated with dose-dependent inhibition of HIV-1 infection. While HIV-1 infection alone did not stimulate the production of pro-inflammatory cytokine production in peripheral mononuclear blood cells, the combination of HIV-1 infection in the presence of the toll-like receptor (TLR4) agonist lipopolysaccharide, resulted in differential cytokine stimulation that was variably blocked by purinergic inhibitors. Conclusion: Our findings distinguish purinergic receptors as key signaling mediators of HIV-1 infection and represent important drug targets that could serve a dual role as both direct anti-retroviral agents and anti-inflammatory agents. Such a class of drugs could reduce the morbidity and mortality associated with chronic HIV-1 disease. 257 AGE AND HIV DO NOT SYNERGISTICALLY IMPACT T-CELL MATURATION OR ACTIVATION Shelli Farhadian 1 , Emilie Jalbert 2 , Yanhong Deng 3 , Matthew B. Goetz 4 , Lesley Park 5 , Amy Justice 6 , Robert Dubrow 3 , Brinda Emu 1 , for theVACS ProjectTeam 1 Yale Univ, New Haven, CT, USA, 2 Univ of Colorado, Aurora, CO, USA, 3 VA Greater Los Angeles Hlth Care System, Los Angeles, CA, USA, 4 Stanford Med, Stanford, CA, USA, 5 VA Connecticut Hlthcare System, West Haven, CT, USA Background: Chronic HIV infection is associated with clinical conditions typically associated with normal aging, suggesting that HIV may cause premature immunosenescence. This study explored whether there is a synergistic impact of age and HIV on T cell phenotypes in HIV infected and uninfected adults. Methods: We performed a cross sectional analysis of HIV-infected (n=111) and uninfected (n=114) male adults from the Veterans Aging Cohort Study. HIV infected subjects were on antiretroviral therapy. Uninfected controls were matched by age, alcohol, and smoking history. All subjects had blood analyzed for T cell markers via flow cytometry. We evaluated the impact of HIV and age on T cell phenotypes using multivariate linear regression models, adjusted for smoking, alcohol and race. Results: HIV infected subjects had an average duration of viral suppression of 4.9 years prior to enrollment blood draw. Their median CD4 count was 566 (IQR 378-769). The median age was 55 (IQR 55-61) in the HIV-infected and 55 (IQR 48-64) in the uninfected. HIV infection was associated with an increased proportion of activated (CD38+ and HLA-DR+) CD8+ T cells (p<0.0001). There was no significant impact of age on the proportion of activated CD8+ or CD4+ T cells. However, as age increased, the proportion of naïve (CD28+ CD27+ CD45RA+) CD8+ T cells decreased (p<0.0001), while the proportion of effector memory (CD28- CD27- CD45RA-) CD8+ T cells increased (p=0.0004). These age effects were found in both HIV infected and uninfected subjects, although HIV infected subjects had an overall higher proportion of effector memory CD8+ T cells at all ages (p=0.0001). With regards to CD4+ T cells, among both HIV-infected and uninfected subjects, older age was associated with decreased proportion of naïve CD4+ T cells (p=0.014). Both HIV and older age were associated with higher proportions of effector memory CD4+ T cells (p<0.0001 and p=0.041). Importantly, there were no significant interactions between HIV infection and age. Conclusion: HIV-associated changes in T cell phenotypes (activated CD8+ T cells and effector memory CD4+ and CD8+ T cells) were not synergistically impacted by age. Likewise, age-associated changes in T cell phenotypes (naïve and effector memory CD4+ and CD8+ T cells) were not dependent on HIV status. These findings suggest that age and HIV status independently affect the immune system, but do not act synergistically to cause accelerated immunosenescence. 258 CELLULAR IMMUNE ACTIVATION IN THE ERA OF CART AND AN AGING HIV+ POPULATION Lesley R. de Armas , Suresh Pallikkuth, Rajendra Pahwa, Stefano Rinaldi, Varghese George, Li Pan, Allan Rodriguez, Margaret Fischl, Gordon Dickinson, Savita Pahwa Univ of Miami, Miami, FL, USA Background: Biological aging is associated with immune activation (IA) due to systemic inflammation, and declining immunity. It is widely accepted that HIV causes persistent IA and premature immunosenescence by approx. 10 years despite cART and virologic suppression. In this study we assessed the impact of IA on Flu vaccine responses in cART-treated HIV infected individuals and healthy controls. Methods: Peripheral blood samples were obtained from 4 participant groups: HIV+ Young (<40yr) (Y+, n=28), HIV- Young (Y-, n=42), HIV+ Old (>60yr) (O+, n=45), and HIV- Old (O-, n=42) prior to (T0) and 3 weeks after (T2) seasonal trivalent inactivated influenza vaccine (TIV) over 3 seasons (2013-16) in which pandemic 2009 H1N1 was included. Vaccine response was measured by hemagluttination titers against H1N1 at T2/T0. All HIV+ participants were on cART for >1 yr and were virologically suppressed. Multi-parameter flow cytometry was performed on T0 PBMC to evaluate IA markers (CD38, HLADR, PD1, ICOS, Ki67) on CD8 and CD4 T cells and subsets including peripheral T follicular helper (pTfh) cells, which are associated with antibody responses. Correlation analysis and Student’s t test were performed to evaluate differences between groups. Results: Vaccine response in participants exhibited the following pattern Y- > Y+> O- = O+. CD4 counts and pTfh (CXCR5+ TCM) frequency were reduced in O- compared to Y- and independently correlated with TIV response, while HIV groups did not show these relationships to CD4 and pTfh. Evaluation of IA markers revealed that 38+DR+ co-expressing cells (CD4 and CD8) were higher in O+ compared to O- but not significantly different from Y+. CD4 and CD8 T cells expressing CD38 alone were equally reduced in O groups compared to respective Y groups. Interestingly, HLADR (CD4 and CD8) expression was elevated in O+ compared to Y+ and HC groups. To determine whether IA expression in HIV impacted TIV response, we performed correlation analysis and found negative correlation with CD4 38+DR+ and positive correlation with pTfh 38-DR- (double negative) cells and T2 H1N1 titers. Conclusion: Our data show differential effects of Aging on IA and TIV response in HC and cART-treated, virologically suppressed HIV individuals. In HIV, TIV response negatively correlated with IA markers (38+HLADR+) but were not affected by CD4 or pTfh frequency, while the opposite was true in HC. This may reflect a poor quality of pre-vaccination pTfh despite sufficient quantity in individuals with virological suppression. 259 ADAR1, A TARGET TO BOOST HIV-1 IMMUNE RESPONSE Maria Pujantell , Ester Ballana, Eva Riveira-Muñoz, Bonaventura Clotet, Jose A. Este IrsiCaixa Inst for AIDS Rsr, Badalona, Spain Background: HIV-1 infection induces innate intracellular antiviral defenses, aimed at restricting virus replication and spread. Controversial data exists regarding the capacity of HIV-1 infection to induce type I IFN and evade immune recognition in macrophages. Therefore, understanding the role and function of innate immune effectors and modulators can help to establish novel strategies for HIV-1 control. Methods: Monocytes obtained from PBMCs were differentiated into macrophages with M-CSF and siRNA was used to inhibit target gene expression. HIV-1 infection was perfomed with VSV-pseudotyped NL4-3 GFP-expressing virus or a full-replicative R5 HIV-1 BaL strain. Proviral DNA formation, viral DNA integration and HIV transcription were quantified by qPCR. Type I IFN production, ISG induction (CXCL10, STAT1 phosphorylation) and innate immune pathway activation (DNA/RNA sensors and IRF3/7 expression and activation) were characterized by qPCR, Western Blot and ELISA. ADAR1-mediated modifications in cellular and viral RNAs were measured by direct sequencing of known ADAR1 target sites. Results: ADAR1 knockdown (siADAR1) in primary macrophages (MDM) led to a significant increase in IFNB1 mRNA (7.5-fold, p=0.03) and CXCL10 gene (1000-fold, p=0.02) and protein expression (2.5-fold, p=0.01) compared to mock-transfected MDM, indicative of innate immune activation. Interestingly, siADAR1 MDM showed a significant reduction in HIV-1 infection either with a single cycle, VSV-pseudotyped NL4-3 GFP expressing virus (75% inhibition, p<0.0001) or a full replicative R5 HIV-1 BaL strain (80% inhibition, p<0.0001). Proviral DNA formation or viral DNA integration were not affected in siADAR1 MDM; however, a significant reduction in viral transcription was detected

Poster and Themed Discussion Abstracts

CROI 2017 103