CROI 2020 Abstract eBook

Abstract eBook

Poster Abstracts

227 KEY FEATURES OF GUT-MICROBIAL DYSBIOSIS IDENTIFIED IN ALCOHOLIC HIV-1 PATIENTS Richa Singhal 1 , Kendall Stocke 1 , Smita Ghare 1 , Manicka Vadhanam 1 , Dmitry Lioznov 2 , Elena Blokhina 2 , Evgeny Krupitsky 2 , Kaku So-Armah 3 , Natalia Gnatienko 3 , Jeffrey H. Samet 3 , Kendall J. Bryant 4 , Robert L. Cook 5 , Matthew Freiberg 6 , Shirish A. Barve 1 1 University of Louisville, Louisville, KY, USA, 2 First Pavlov State Medical University of St Petersburg, St Petersburg, Russian Federation, 3 Boston University, Boston, MA, USA, 4 National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, USA, 5 University of Florida, Gainesville, FL, USA, 6 Vanderbilt University, Nashville, TN, USA Background: Heavy alcohol drinking and HIV-1 infection are independently associated with the development of gut-microbial dysbiosis and increase in intestinal permeability and microbial translocation. These gut-associated events are major pathogenic factors driving local and systemic inflammation and development of comorbidities. Significantly, the combinatorial effects of HIV-1 infection with a history of heavy alcohol consumption have not been determined. We will evaluate the qualitative and quantitative changes occurring in the gut microbiome (dysbiosis) associated with heavy alcohol consumption in people living with HIV (PLWH) Methods: Fecal samples were obtained, from 102 participants in the St PETER (Russia) HIV and alcohol use cohort (RCHIV-Alc). Metagenomics analysis of the 16S rRNA gene was done by amplification of V3-V5 regions, on the Illumina MiSeq platform. Operational taxonomic units (OTUs) tables profiling microbiome were generated using QIIME. Important statistical analyses included LEfSe (Linear discriminant analysis Effect Size), Pearson’s correlation, multivariate analysis, Mann- Whitney U test and ANOVA with Tukeys correction. Cytokine levels were determined using the MSD platform Results: Metagenomics analysis revealed that as compared to control, RCHIV-Alc patients showed a major loss of butyrate producing bacteria. This loss correlated with a decrease in microbial diversity and F/B ratio along with an increase in immune activation and inflammation markers sCD14, IL6 and MIP-1b (Table 1A,B). Further, LEfSe analysis determined that there was a significant enrichment of pathogenic Enterobacteriaceae (LDA score > 1.5, p < 0.05), only in very heavy alcohol drinking RCHIV-Alc patients with an AUDIT score≥20 (Table 1A). Significantly, this increase in Enterobacteriaceae also correlated with a decrease in microbial diversity and CD4+ counts along with a concomitant increase in viral load and TNFa, IFNg, IL-6, IL-8, MCP-1, MIP-3a and sCD14(Table1B) Conclusion: The study identifies a significant loss of butyrate producing bacteria in RCHIV-Alc patients. Notably, in a subset of HIV patients with very heavy alcohol use (AUDIT score≥20) the gut microbial dysbiosis is further characterized by a significant enrichment of “pro-inflammatory” Gram negative bacteria represented by Enterobacteriaceae. These findings identify the characteristics of gut microbial dysbiosis occurring in response to the combinatorial effects of alcohol and HIV-1 infection that can adversely affect HIV-1 pathogenesis

228 PREVOTELLA IS RELATED TO A DYSREGULATION OF IFN AND T-CELL RESPONSE IN HIV INFECTION Claudia Pinacchio 1 , Giuseppe P. Innocenti 1 , Letizia Santinelli 1 , Eugenio Nelson Cavallari 1 , Federica Frasca 1 , Carolina Scagnolari 1 , Guido Antonelli 1 , Claudio M. Mastroianni 1 , Gabriella d'Ettorre 1 1 Sapienza University of Rome, Rome, Italy Background: Altered interplay between gut mucosa and dysbiotic microbes during HIV infection has been linked to chronic immune dysfunction, commonly characterized by high levels of IFN and immune activation markers as well as by a severe depletion of Th17 T cells in the gastrointestinal tract. We hypothesized that a specific gut microbial communities imbalance in HIV-infected individuals could affect the antiviral defense and T cell immunity. Methods: Ten HIV-infected subjects on long-term suppressive combined antiretroviral therapy (cART) underwent endoscopic procedures and blood collection. Lamina propria lymphocytes were isolated from five different intestinal sites (e.g. terminal ileum, cecum, ascending, transverse, and descending colon). Phylum, Family, Class, Order and Genus identification was performed on bacterial 16S ribosomal DNA sequences obtained from fecal samples collected for all patients. Measurements of CD4 and CD8 T cell activation (CD38+, HLA-DR+, CD38+HLADR+) and IFNγ and IL-17 expression on both CD4+ (Th1, Th17) were performed by flow cytometry. Gene expression level of IFNβ, IFN receptor 1(IFNAR1) and the well-known Interferon Stimulated Gene(ISG), Myxovirus resistance gene A(MxA), was also evaluated in both anatomical sites by RT/real-time PCR. Nonparametric t-tests were used for statistical analysis. Results: Fecal microbiota analyses confirmed that all HIV-1 individuals showed a distinct pattern of gut microbiota composition characterized by elevated levels of the genus Prevotella(relative abundance of 6.10%). Abundance of Prevotella was directly correlated with CD4+38+, CD4+DR+ and CD4+38+DR+ in both peripheral blood and gut (p<0.05 for all these measures). Additionally, the same trend was observed for the activated CD8+ T cell subsets in both compartments. By contrast,Prevotella levels were inversely associated with the frequencies of Th17 T cells in blood (R=-0,454, p=0,00005)and in gut compartment (R=- 0,284, p=0.01). Notably, higher levels of IFNβ(R=-0.662, p=0.042), MxA(R=- 0.774, p=0.012), and IFNAR1(R=-0.662, p=0.042), were associated to lower abundance of the genus Prevotella in the gut mucosa. Conclusion: Our findings suggest that abundance of the genus Prevotella could affect gut mucosal type I IFN pathways and modify T cell response in HIV-infected subjects. 229 ANTIINFLAMMATORY EFFECT OF METFORMIN ON MICROBIOTA IN NONDIABETIC PEOPLE WITH HIV Stéphane Isnard 1 , John Lin 1 , Brandon Fombuena 1 , Thibaut V. Varin 2 , André Marette 2 , Delphine Planas 3 , MeriemMessaoudene 3 , Bertrand Routy 3 , Claude P. Van Der Ley 4 , Ido Kema4, Petronela Ancuta 3 , Jonathan Angel 5 , Jean-Pierre Routy 6 1 McGill University Health Centre Research Institute, Montreal, QC, Canada, 2 Laval University, Quebec City, QC, Canada, 3 Centre de Recherche du CHUM, Montreal, QC, Canada, 4 University Medical Center Groningen, Groningen, Netherlands, 5 University of Ottawa, Ottawa, ON, Canada, 6 McGill University Health Centre, Glen site, Montreal, QC, Canada Background: People living with HIV (PLWH) on antiretroviral therapy (ART) remain at increased risks of inflammatory comorbidities. Metformin, an anti- diabetic drug with anti-aging effect, was shown to decrease inflammation by improving glucose metabolism and changing gut microbiota composition in diabetic people. Herein, we report results from the LILAC (CIHR/CTN PT027) clinical trial evaluating the effect of 12 weeks of metformin on blood/gut inflammation and gut microbial composition in PLWH on ART. Methods: A total of 22 non-diabetic (HbA1c <6%) PLWH, on ART with viral load <50 copies/ml for more than 3 years and CD4/CD8 ratio ≤0.7, received 12 weeks of metformin 850 mg bid. Blood and stools were collected at baseline (V1), after 12 weeks of metformin (V2), and 12 weeks after metformin discontinuation (V3). Soluble CD14 was measured in plasma. DNA was extracted from stools and 16S rRNA sequenced. Bacterial microbiota composition variations were analyzed using LefSe. Serum short chain fatty acids (SCFA) were measured by LC-MS. The beneficial Akkermansia muciniphila, enriched in stools of diabetic people initiating metformin, was quantified by qPCR. Results: CD4 T-cell count, CD4/CD8 and HbA1c levels did not vary between visits, however plasma sCD14 levels decreased at V2 and V3 compared to V1.

Poster Abstracts

77

CROI 2020