CROI 2018 Abstract eBook

Abstract eBook

Poster Abstracts

Background: Understanding the biological correlates of HIV susceptibility in young women is critical for prevention efforts, but these are not well defined. Here we utilized a metaproteomics approach to identify cervicovaginal host and bacterial factors underlying HIV acquisition risk in women from the CAPRISA 004 trial, and examined functional relationships using rhesus macaques (RM) and in vitro models. Methods: Cervicovaginal lavage samples from last HIV negative time point in 63 women who acquired HIV within the trial (cases), and 638 women who remained uninfected, were analyzed by mass spectrometry. A total of 5,335 host and bacterial proteins were identified. Cox PH models and hierarchical clustering were used to determine relationships to risk of HIV infection. Bacterial co-cultures were used to study bacteria-proteome interactions. In vivo immunofluorescense and RNAseq data of early infectious foci was collected from vaginal mucosal tissues of dual-reporter SIV/SIV challenged RM’s. Results: Twenty proteins were differentially abundant in cases (P<0.05, HR>1.6, FD>1). Eleven downregulated proteins best classified cases from controls by cluster analysis (OR: 3.7 (2.1-6.6), P=2.21E-6). These localized to the upper vaginal epithelium signifying epithelial barrier disruption (EBD). Women with EBD had similar baseline characteristics to those without EBD, and adjustments for STI’s, contraceptive usage, sexual behaviors, and other criteria did not impact these findings. In vaginal tissue of SIV-challenged RM, GSEA and immunofluorescence showed HIV risk proteins could distinguish virus susceptible from non-susceptible sites (NES=1.95, P<0.0001). EBD was most frequent in women with vaginal community state type (CST) IV bacteria (Prevotella, Mobiluncus, others) (OR: 4.57 (2.45-8.64), P=8.5E-07). CST-IV bacteria reduced EBD protein expression in vaginal epithelial cells in vitro (P<0.05). HIV risk with EBD was exacerbated by CST-IV bacteria (Interaction P=0.0393); women with both EBD and CST-IV bacteria were the highest risk group identified, with a 8.9-fold increase compared to women without EBD and CST-I bacteria (L. crispatus) (HR=9.89 (4.01-24.37), P=1.4E-4). Conclusion: This study identifies a high-risk phenotype and provides evidence that epithelial disruption exacerbated by vaginal bacteria increases HIV acquisition risk in young women, which may represent vulnerable tissue sites favorable for virus. Strategies reducing bacteria-associated EBD may decrease HIV acquisition in young women. 272 IMPAIRED GUT TIGHT JUNCTION BUT PRESERVED ΓΔ AND MICROBIAL TRANSLOCATION IN ACUTE HIV Elvira S. Cannizzo , Giuseppe Ancona, Delfina Tosi, Federica Savi, Camilla Tincati, Antonella D’Arminio Monforte, Giulia Marchetti University of Milan, Milan, Italy Background: Disruption of gastrointestinal integrity and subsequent microbial translocation (MT) are hallmarks of chronic HIV infection (C-HIV). Likewise, γδ T-cells are deeply affected in number and function. Despite their pivotal role in mucosal immunity, few data are available on gut-associated γδ T-cells during HIV. Thus, we aimed to comparatively investigate circulating and gut-associated γδ T-cells in primary (P-HIV) and C-HIV infection and their possible association with gut Junctional Complexes (JC) and MT. Methods: In 14 P-HIV patients (pts, Fiebig I-V), 15 C-HIV and 10 age-matched healthy controls (HC) we measured in peripheral blood (PB): (i) γδ frequency (CD3+panγδ+Vδ1+Vδ2+), (ii) γδ and CD3+ exhaustion (CD8/PD1/CD95/39), maturation (CCR7/CD45RA), cytolytic activity (granzyme B/CD107a), gut-homing (α4β7/CCR9/CD103) (Flow Cytometry, FC) (iii) T-cell activation (CD8/CD38/ HLADR) (iv)Th17 (CD3/CCR6/CD161) (FC); (iv) plasma MT (I-FABP, sCD14, EndoCAb) (ELISA). On colon/ileum biopsies: (i) tight junction (TJ) proteins (CDh1, ZO-1) (Immunohistochemistry, IHC), (ii) T-cell count (CD3, CD4, CD8) (FC); (iii) γδ quantification (FC and IHC). Chi-square, Mann-Whitney test were used. Results: Fig. 1A shows the clinical characteristics of P-HIV and C-HIV pts. Compared to HC, C-HIV and P-HIV displayed equally contracted ileum/colon CD4+ and CDh1 and ZO-1, with TJ immunostaining being distributed only at the basolateral cell surface and not around the entire epithelial surface (Fig.1B-C). Despite the CDh1/ZO-1 zonal loss, P-HIV featured lower circulating I-FABP and sCD14 vs C-HIV, comparable to HC (Fig.1D-E), suggesting contained gut damage and MT. Interestingly, gut γδ T frequency seemed conserved in P-HIV vs C-HIV (Fig. 1F). In PB, P-HIV showed heightened activated CD8+/CD4+CD38+HLA- DR+, lower exhausted CD95+CD8+ and similar Th17-like CD3+CD161+CCR6+ vs C-HIV (Fig.1G). Both P-HIV and C-HIV displayed a higher Vδ1 vs Vδ2 cells, in contrast with Vδ2 predominance in HC (Fig. 1H), consistent with an inversion

of the physiologic Vδ2/Vδ1 ratio. Moreover, P-HIV featured higher Vδ2 cells (p=0.004) (Fig.1I) with gut homing phenotype (p=0.02) (Fig.1L). Conclusion: Despite the damaged JC, early-infected HIV pts still contain MT, possibly due to an enrichment in gut-associated γδ cells known to positively regulate mucosal homeostasis. Further, the inverted plasma Vδ2/Vδ1 ratio with outgrowth of gut-homing Vδ2, confirms subverted γδ balance with ongoing gut recruitment.

Poster Abstracts

273 MICROBIAL DYSBIOSIS DOES NOT ALTER DISEASE PROGRESSION IN SIV- INFECTED ASIAN MACAQUES Alexandra Ortiz 1 , Sarah DiNapoli 1 , Jacob Flynn 1 , Carly Elizabeth C. Starke 1 , Stephen Lai 1 , Mackenzie Long 1 , Ornella Sortino 1 , Carol Vinton 1 , Joseph Mudd 1 , Jacob D. Estes 2 , Jason Brenchley 1 1 NIH, Bethesda, MD, USA, 2 NCI, Rockville, MD, USA Background: Progressive HIV infection is associated with systemic immune activation that is not fully ameliorated with effective antiretroviral therapy. Measures of immune activation – including elevated concentrations of circulating pro-inflammatory cytokines, low frequencies of intestinal TH17 cells, and exacerbated T-cell activation – have been shown to correlate with the enrichment of disease-associated intestinal microflora, namely an expansion of bacteria within the phylum Proteobacteria at the expense of the Firmicutes and Bacteroidetes. Although several studies have indicated that the therapeutic administration of probiotic, or commensal species may significantly improve disease progression in non-human primate models of HIV infection, an empirical assessment of the contribution of microbial dysbiosis to disease progression has not yet been executed. Methods: To assess the contribution of microbial dysbiosis to untreated lentiviral disease progression, we administered vancomycin (10 mg/kg p.o.; 5 doses/month) to 7 rhesus macaques prior to and throughout SIV infection. Prior to infection, vancomycin treatment resulted in a significant increase in the frequency of fecal Proteobacteria and Fusobacteria and a concordant decrease in Bacteroidetes and Firmicutes, as compared to 6 control animals. We infected all animals with SIVmac239 and routinely measured lymphocyte frequency and function by polychromatic flow cytometry, viral loads by SIV-Gag qRT-PCR, and fecal microbial frequencies by 16S sequencing by Illumina. Results: Fecal microbial instability was evident throughout SIV infection, with increased frequencies of Deltaproteobacteria and Gammaproteobacteria, and

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CROI 2018