CROI 2020 Abstract eBook

Abstract eBook

Poster Abstracts

Bacterial alpha diversity tended to increase at V2 and V3. However, we observed a significant increase of Escherichia/Shigella and Lachnoclostridium and a decrease of Collinsella abundance at V2 compared to V1. The abundance of Lachnospiraceae, which are specialized in butyrate production, was increased at V3 compared to V1. Accordingly, we found increased serum butyrate/ isobutyrate levels at V2 and V3 compared to V1. No differences were observed for other SCFA propionate, succinate and methylmalonate. A. muciniphila abundance remained stable between visits. Conclusion: A 12-week metformin therapy in non-diabetic PLWH on ART decreased plasma levels of the inflammation marker sCD14 in association with an enrichment of butyrate-producing bacteria in stools and increased serum butyrate levels. To confirm our study findings, a longer metformin treatment should be conducted in non-diabetic PLWH. 230 FUNCTIONAL RESTORING OF GUT BARRIER AFTER MODULATION OF INTESTINAL MICROBIOTA Letizia Santinelli 1 , Ranieri Verin 2 , Giuseppe P. Innocenti 1 , Claudia Pinacchio 1 , Eugenio Nelson Cavallari 1 , Gabriella De Girolamo 1 , Anna Maria Pronio 1 , Guido Antonelli 1 , Giancarlo Ceccarelli 1 , Carolina Scagnolari 1 , Vincenzo Vullo 1 , Claudio M. Mastroianni 1 , Giacomo Rossi 3 , Gabriella d'Ettorre 1 1 Sapienza University of Rome, Rome, Italy, 2 University of Liverpool, Liverpool, UK, 3 University of Camerino, Camerino, Italy Background: A complex series of events starting from enterocytes modifications, mucosal immune dysfunction, damage to the intestinal epithelial barrier, microbial translocation, and chronic systemic immune activation, contribute to HIV disease progression. This study aimed to verify whether the modulation of microbiota plays a role in restoring the intestinal barrier integrity focusing on cellular morphology, cellular apoptosis machinery and mitochondrial restoring. Methods: 10 Caucasian cART-treated HIV-1+ patients and 10 healthy age and gender matched controls were recruited at the Department of Public Health and Infectious Diseases, Sapienza University of Rome (Italy). HIV+ participants received for six months two sachets, each containing 450 × 109 billion bacteria, twice a day of Vivomixx®. All patients underwent to pancolonoscopy and blood sampling before (T0) and after 6 months of probiotic supplementation (T6). Cellular morphology, cellular apoptosis machinery and mitochondrial restoring were analyzed in mucosal biopsies taken from different colonic tracts of intestine at T0 and T6. Results: After the probiotic administration, sections of intestinal mucosa showed an improvement of epithelial integrity and a reduction of diffuse interstitial inflammatory infiltrate. The rate of enterocytes, undergoing apoptosis both in epithelium and intestinal crypts, was significantly reduced at T6 (p=0.04). Mitochondria number and size differed from the 2 groups of patients (p>0.05): samples taken at T6 showed significant increased number of larger mitochondria and the levels of these organelles were similar to healthy samples (p>0.05).Ultrastructural morphological data regarding mitochondria were confirmed by mt-DNA evaluation at T6 that indicated an increase concentration of mitochondria in all tested patients (p<0.005) and a similar trend for CYCC concentration (p<0.005), with substantial reduction of HSP60 and 70 m-RNA expression in mucosal biopsies (p<0.005). LPS and cCK18 plasma levels significantly decreased at T6 (p<0.05). Conclusion: The modulation of intestinal microbiota ameliorates histopathologic alterations characterizing HIV enteropathy, reducing inflammatory cells infiltration,villous blunting and widening, vacuolated enterocytes, crypt hyperplasia. All these data are in accord with a decrease in LPS and cCK18 plasma levels after probiotic supplementation, respect to levels that were observed at baseline. 231 CELLULAR STRESS BIOMARKERS ARE ASSOCIATED WITH MARKERS OF MICROBIAL TRANSLOCATION Carol Vinton 1 , Carly E. Starke 1 , Alexandra Ortiz 1 , Ornella Sortino 1 , Kenneth Knox 2 , Irini Sereti 1 , Jason Brenchley 1 1 NIH, Bethesda, MD, USA, 2 University of Arizona, Tucson, AZ, USA Background: Microbes and microbe components that translocate from the lumen of the GI tract can directly stimulate the immune system and contribute to inflammation. Given that microbial translocation occurs in many chronic diseases, defining reliable biomarkers that reflect microbial translocation is essential for proper inflammatory diagnoses. Host proteins produced in response to microbial antigenic stimulation are often used as surrogates of

microbial translocation; however, many of these can be produced in response to self-proteins produced by dead and dying cells. We measured levels of biomarkers associated with GI damage, innate immune responses, and cell death associated proteins in cohorts of HIV-infected individuals and SIV- uninfected and infected pigtail and rhesus macaques to identify potentially confounding contributors to microbial translocation biomarkers. Methods: We measured plasma levels of sCD14, HMGB1, RAGE, IFABP, and zonulin by ELISA in human and non-human primates (NHPs). Our cohorts consisted of 38 ARV-naïve and treated HIV-infected human patients; 9 pigtail macaques (PTs) and 12 rhesus macaques (RMs) longitudinally pre-SIV and during acute and chronic infection; and an unmatched cohort of 6 chronically SIV-infected RMs and 6 SIV-uninfected RMs Results: We observed significant reductions in systemic levels of sCD14 and RAGE post-ARV in HIV-infected individuals. sCD14, HMGB1, and IFABP levels increased in chronically SIV-infected NHPs relative to their pre-infection plasma levels. Surprisingly, both sCD14 and zonulin levels decreased longitudinally, pre- to acute-SIV infection. No markers strongly associated with sCD14 consistently in all three groups. In humans, sCD14 associated most strongly with HMGB1 plasma levels. However, in NHPs, sCD14 only correlated with RAGE levels in the RM cohort. The strongest association between markers within the NHP cohort was between RAGE and IFABP (P<0.0001). Conclusion: Our data suggest that cellular proteins which are secreted during generalized cellular stress, and which specifically induce sCD14 production may contribute to elevated levels of sCD14 observed in HIV/SIV-infected individuals. These cellular stress biomarkers, specifically RAGE and IFABP may be released into circulation due to epithelial barrier damage. 232 CMV SEROPOSITIVITY AND MICROBIAL TRANSLOCATION IN HIV ELITE CONTROLLERS Rayoun Ramendra 1 , Stéphane Isnard 1 , John Lin 1 , Brandon Fombuena 1 , Jing Ouyang 1 , Franck P. Dupuy 1 , Yonglong Zhang 2 , Malcolm Finkelman 2 , Ido Kema 3 , Cécile Tremblay 4 , Nicole Bernard 1 , Jean-Pierre Routy 1 , for the Canadian Cohort of HIV+ Slow Progressors and Montreal Primary HIV Infection Study Groups 1 McGill University Health Centre Research Institute, Montreal, QC, Canada, 2 Associates of Cape Cod, Inc, Falmouth, MA, USA, 3 University Medical Center Groningen, Groningen, Netherlands, 4 Centre de Recherche du CHUM, Montreal, QC, Canada Background: Elite controllers (EC) are people living with HIV (PLWH) who maintain plasma HIV viral load below 50 copies/mL without antiretroviral therapy. However, EC present with chronic inflammation and remain at increased risk of developing non-AIDS comorbidities. Microbial translocation is a contributor to chronic inflammation and CMV co-infection has been recently linked to increased gut damage. We previously reported that CMV seropositivity was associated with elevated epithelial gut damage and microbial translocation in ART-treated PLWH and HIV-uninfected controls. As Canada has one of the lowest CMV co-infection prevalence in the world, we evaluated the link between CMV seropositivity, microbial translocation, and inflammation among EC. Methods: Study samples were collected from 37 EC (25 CMV+, 12 CMV-). By HLA typing, we categorized participants with/without protective HLA alleles (B*27, B*57, B*58, n=16). We measured CD4 and CD8 T-cell counts, anti-CMV IgG and anti-EBV IgG titers, markers of epithelial gut damage REG3a and I-FABP, markers of microbial translocation LPS, sCD14 and B-D-Glucan (BDG), as well as total IgG, IgM, IgA, IL-1B, IL-6 and kynurenine/tryptophan. Results: As expected, participants with protective HLA alleles had higher CD4 T-cell count compared those without protective alleles (p=0.03). Plasma levels of markers of epithelial gut damage and microbial translocation were similar among EC with and without protective HLA alleles. CMV seropositive and seronegative EC presented with similar age, male/female ratio, and CD4 T-cell counts. Conversely, CMV seropositive EC had elevated CD8 T-cell counts (p=0.002), I-FABP (p=0.01), sCD14 (p=0.04), LPS (p=0.02), BDG (p=0.02), IL-1B (p=0.001), IL-6 (p<0.001), and kynurenine/tryptophan ratio (p=0.002) compared to CMV seronegative EC. Moreover, anti-CMV IgG titers were also associated with plasma levels of I-FABP (r=0.48; p=0.02), sCD14 (r=0.3; p=0.05), LPS (r=0.42; p=0.04), BDG (r=0.69; p<0.001), IL-1B (r=0.52; p=0.01), and IL-6 (r=0.37; p=0.05). Conversely, anti-EBV IgG titers and total IgG, IgM, IgA were not associated with these markers. Conclusion: Markers of epithelial gut damage, microbial translocation, and inflammation were higher in CMV seropositive EC, irrespective of protective HLA

Poster Abstracts

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CROI 2020