CROI 2019 Abstract eBook

Abstract eBook

Poster Abstracts

Conclusion: The uncircumcised penis is enriched with sub-preputial anaerobes; the abundance of some of these anaerobes has been associated with HIV acquisition risk. HIV-associated anaerobes are associated with sub-preputial levels of the chemoattractant cytokine IL-8. Although collinearity of bacteria in the uncircumcised penile microbiome makes it difficult to assess independent IL-8 associations, only a subset of species were linked to the density of putative HIV target cells in the underlying foreskin tissue.

242 BLOOD MICROBIOTA CORRELATES WITH INFLAMMATION AND ART- MEDIATED IMMUNE RESTORATION Sergio Serrano-Villar 1 , Mariano Matarranz 2 , Jose I. Bernardino 3 , Alejandro Vallejo 1 , Carolina Gutiérrez 1 , Otilia Bisbal 2 , Maria Lagarde 2 , Nadia Madrid 1 , Rafael Rubio 2 , Cristina Gomez-Ayerbe 1 , María J. Vivancos-Gallego 1 , Alfonso Cabello 1 , Matilde Sanchez-Conde 1 , Vicente Estrada 4 , Santiago Moreno 1 1 Hospital Ramón y Cajal, Madrid, Spain, 2 Hospital Universitario 12 de Octubre, Madrid, Spain, 3 Hospital La Paz Institute for Health Research, Madrid, Spain, 4 Hospital Universitario Clínico San Carlos, Madrid, Spain Background: HIV infection impairs the mucosal immunity and leads to bacterial translocation, fueling chronic inflammation and disease progression. The compositional profile of the translocated bacteria remains undefined. Methods: A total of 80 samples from 50 individuals were studied: 30 HIV- infected individuals with <350 CD4+ T-cells/uL or AIDS at diagnosis and after 48 weeks of first-line ART, and 20 controls matched by sex and age. HIV+ subjects were categorized by the median CD4/CD8 ratio fold increase during ART (cut-off: 2.5) to classify study participants as immunological responders (IR) or non-responders (INR). Total DNA was extracted from 50 uL of blood and was analyzed by highly sensitive 16S rDNA targeted metagenomic sequencing of V3-V4 regions using MiSeq Illumina and the FROGS metagenomic workflow. LEfSe analysis was used to identify bacterial biomarkers. Their correlations which markers of inflammation, bacterial translocation and peripheral T cell activation was calculated using Spearman’s regression. Results: Alpha diversity was significantly higher in HIV+ vs. HIV- subjects, and these differences were attenuated after 48 weeks of ART. We did not detect differences in beta diversity. LEfSe analysis revealed that HIV+ subjects showed enrichment for several pathobionts, including Flavobacterium, Haemophilus, Chitinophagaceae, and Lactobacillales, and depletion of Pseudomonas and Rubrobacter. This pattern of dysbiosis was attenuated after 48 weeks of ART, yet we still found enrichment for Escherichia, Shigella, Ralstonia, Achromobacter, Pandoreae and depletion of Rubrobacter and Micrococcaceae. At baseline, enrichment for Lactobacillales, Nocardiaceae, Flavobacterium and Rhodococcus predicted greater immune recovery and depletion of Actinobacteria, Moraxellaceae and Corynebacteriacae. We selected the most enriched (Lactobacillales) and depleted (Actinobacteria) bacteria for correlation analyses. These taxa significantly correlated with changes in IL6, sCD163, LTA and CD8 T cell activation. Conclusion: HIV infection affects the composition of the blood microbiota by increasing the abundance of pathobionts. ART appears to attenuate these compositional abnormalities. Different translocated bacteria were predictive of the extent of immune recovery after 48 weeks of ART and significantly correlated with markers of inflammation, bacterial translocation and immunoactivation. Hence, these taxa may prove functionally relevant for HIV immunopathogenesis and deserve further investigation.

241 HIV-SUPPRESSED PATIENTS’ PLASMA AND SEMEN EXOSOMES CONTAIN PROTECTIVE LEVELS OF ART Jennifer L. Welch 1 , Jack T. Stapleton 1 , Hussein Kaddour 2 , Lee Winchester 3 , Courtney V. Fletcher 3 , Chioma M. Okeoma 2 1 University of Iowa, Iowa City, IA, USA, 2 Stony Brook University, Stony Brook, NY, USA, 3 University of Nebraska Medical Center, Omaha, NE, USA Background: Exosomes are non-viral vesicles released from cells with diverse cellular effects that may influence HIV-1 pathogenesis. In vitro, HIV-1-infected cells release exosomes that promote pathogenesis, whereas healthy-donor derived breast-milk, vaginal fluid, and semen exosomes inhibit HIV-1. Little is known regarding the effect of HIV-infected donors’ body fluid exosomes. Here, we characterize the function of exosomes from HIV-infected donor plasma and semen to examine their impact on HIV-1 infection. Methods: Exosomes were isolated from plasma and semen of HIV-positive ART-naïve persons with >50,000 HIV RNA copies/mL (n=3); HIV-positive ART- suppressed with <50 HIV RNA copies/mL (n=13), and HIV-uninfected (healthy) controls (n=6). Exosome inhibition of HIV-1 NL4.3 replication was determined in TZM-bl cells. Exosome-associated ART levels (tenofovir: TFV, TFV-diphosphate; emtricitabine: FTC, FTC-triphosphate; dolutegravir: DTG; and efavirenz: EFV) were measured by LC-MS/MS. ART was loaded onto HIV-uninfected exosomes using ExoFect™ exosome transfection. Results: Semen exosomes (SE) but not plasma exosomes (BE) from HIV- uninfected and HIV-positive ART-naïve donors inhibited HIV-1 (47% and 62% inhibition, respectively). SE and BE prepared from HIV-infected, ART-suppressed values for all drugs measured (TFV, FTC, DTG, and EFV). TFV and FTC were more abundant in SE fractions than in BE while DTG and EFV were more abundant in the BE fractions, though this did not reach statistical significance. Loading HIV-negative BE with ART confirmed that exosome-associated ARVs mediated protection against HIV-1. Conclusion: Although semen is the main vector in sexual transmission, it contains exosomes that inhibit HIV-1 independent of donor HIV or ART status. Thus, SE may contribute to the low rates of sexual transmission observed in vivo (1/200-1/1000 sexual events). Plasma and seminal exosome fractions from HIV-positive ART-suppressed donors inhibited HIV-1. ARVs and their active metabolites were detected in HIV-positive suppressed donors’ body fluid exosomes at biologically relevant, inhibitory levels. Further, ART-loaded exosomes inhibited HIV-1 replication, indicating that exosomes could play a role in HIV-1 drug delivery. donors reduced HIV-1 replication in TZM-bl cells (>75% inhibition), and contained concentrations of antiretroviral (ARV) medications above the IC 50

Poster Abstracts

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CROI 2019