CROI 2019 Abstract eBook

Abstract eBook

Poster Abstracts

231 EFFECTS OF LACTOFERRIN ON IMMUNE ACTIVATION AND MICROBIOME AMONG HIV+ INDIVIDUALS Ornella Sortino 1 , Katherine Huppler Hullsiek 2 , Elizabeth Richards 3 , Adam Rupert 1 , Andrea Schminke 4 , Namo Tetekpor 4 , Mariam Quinones 3 , Rachel Prosser 4 , Timothy Schacker 2 , Irini Sereti 3 , Jason V. Baker 2 1 Leidos Biomedical Research, Inc, Frederick, MD, USA, 2 University of Minnesota, Minneapolis, MN, USA, 3 NIH, Bethesda, MD, USA, 4 Hennepin Healthcare Research Institute, Minneapolis, MN, USA Background: Irreversible injury to gut mucosa with loss of epithelial integrity and translocation of microbial antigens represents a potential mechanism driving immune activation, and subsequent clinical risk, among ART-treated HIV+ individuals. Lactoferrin is an endogenous iron-binding protein that binds lipopolysaccharide, improved outcomes among those with sepsis, and has immunomodulatory properties that could reduce HIV-associated inflammation. Methods: Treatment effects of oral recombinant human rh-lactoferrin versus placebo were investigated in a randomized, double-blind, cross-over clinical trial, among participants ≥40 yrs with suppressed plasma HIV RNA receiving ART. Plasma, serum and peripheral blood mononuclear cell (PBMC) specimens were collected and cryopreserved at baseline and months 1 and 3 of each 3-month cross-over period. Soluble biomarkers were measured with ELISA, ELFA (D-dimer) or electroluminescence methods, and immune phenotyping of monocytes, T cells and Mucosal Associate Invariant T cells by LSRII flow cytometer. The treatment effect was calculated for each biomarker with longitudinal mixed models. A rectal swab specimen was collected before and after study drug exposure among a subset of participants for microbiome study. The QIIME 2.0 was used for a pairwise group comparison test. Results: 54 participants were randomized and received study drug, with 50 completing the first period and 46 completing the second period. Median age was 51 years and CD4+ count was 651 cells/mm3; 89%were male, 72%white, and 39%with prior AIDS. Adherence and adverse events did not differ between rh-lactoferrin and placebo periods. Results for representative biomarkers and immunophenotyes are shown in Table 1, with no consistent evidence of a treatment effect demonstrated. The percent serum iron saturation significantly increased on rh-lactoferrin versus placebo by 2.6% (95%CI: 0.2, 5.0), but this effect did not reach significance for ferritin (5.8 ng/mL; 95%CI: -3.3, 15.0). Among a subset (n=12), intestinal microbiota analysis revealed stability in α and β diversity and in the abundance of Bacteroidetes and Firmicutes members over follow-up with no discernible treatment effect from rh-lactoferrin. Conclusion: Oral rh-lactoferrin administration among HIV+ individuals receiving ART with viral suppression was safe and well tolerated, but had no effects on systemic inflammation or cellular immune activation, and exerted no changes in gut microbiome.

Jane Deayton 1 , Moira J. Spyer 7 , Nigel Klein 7 , Sarah Walker 7 , Diana Gibb 7 , Amee R. Manges 2 , Andrew Prendergast 1 1 Queen Mary University of London, London, UK, 2 University of British Columbia, Vancouver, BC, Canada, 3 University of Zimbabwe, Harare, Zimbabwe, 4 MRC Uganda Virus Research Institute, Entebbe, Uganda, 5 Baylor College of Medicine Children’s Foundation, Kampala, Uganda, 6 Makerere University College of Health Sciences, Kampala, Uganda, 7 University College London, London, UK Background: Long-term cotrimoxazole prophylaxis reduces mortality and morbidity in HIV infection but the mechanisms underlying these sustained clinical benefits are unclear. We have previously shown that long-term continuation of cotrimoxazole reduces systemic inflammation, a driver of mortality, in HIV+ ART-treated children. Here we explore the mechanisms that underlie the anti-inflammatory benefits of cotrimoxazole. Methods: Circulating inflammatory mediators (CRP, IL-6, TNFα and soluble CD14) were quantified in plasma samples from HIV-positive Ugandan and Zimbabwean children receiving antiretroviral therapy in the ARROW trial randomised to continue (n=149) versus stop (n=155) cotrimoxazole. Using an in vitro model of systemic inflammation, we evaluated the direct effect of cotrimoxazole on immune cell activation in blood samples from HIV-positive (n=16) and HIV-negative (n=8) UK adults who were cotrimoxazole-naive. Since HIV enteropathy can drive systemic inflammation, we quantified biomarkers of intestinal inflammation (myeloperoxidase, neopterin, alpha-1-anti-trypsin and REG1β) and microbiome composition using randomised stool samples from ARROW. In a parallel in vitro model of gut inflammation (Caco-2 gut epithelial cell transwell cultures), we assayed the effect of cotrimoxazole on epithelial barrier function and chemokine production. Results: Inflammatory biomarkers (CRP and IL-6) were significantly lower among children continuing cotrimoxazole. This was not explained by global differences in symptomatic illness, viral suppression, CD4+ T-cell counts or activation status, or sub-clinical gut pathogen carriage. In vitro cotrimoxazole treatment reduced pro-inflammatory cytokine production in response to pathogen antigens by both HIV+ and HIV- adults. In stool samples from ARROW, myeloperoxiadse levels were significantly lower in children continuing cotrimoxazole 84 weeks post-randomisation and this was associated with suppression of viridians group Streptococci and their mevalonate metabolism. Cotrimoxazole-treated Caco-2 produced less IL-8 in vitro. Conclusion: Cotrimoxazole reduces systemic and intestinal inflammation both through its antibiotic properties and by direct immunomodulation of leukocytes and gut epithelial cells. Synergy between these pathways may contribute to the sustained clinical benefits of long-term cotrimoxazole prophylaxis despite high antimicrobial resistance, providing a further rationale for extending coverage among people living with HIV in sub-Saharan Africa. Background: HIV infection results in damage to the gastrointestinal (GI) immune system that is incompletely restored with antiretroviral (ARV) therapy. Recent findings have implicated that GI immune system competency is dependent upon signaling originating from the commensal microbiota and that the composition of the microbiome is altered in some diseased states (dysbiosis). In Asian macaque models of HIV infection, we noted that the initiation of ARV therapy - though not SIV-infection itself - was associated with dysbiosis. Similar to HIV-infected humans, this dysbiosis was characterized by an enrichment for Gammaproteobacteria at the expense of Clostridia sub-taxa. We thus postulated that ARVs might themselves contribute to dysbiosis and non-AIDS related comorbidities. Methods: We treated 6 healthy rhesus macaques (RM; Macaca mulatta) with a Darunavir-Ritonavir (DRit) protease inhibitor regimen (400mg and 100mg b.i.d. respectively) for 90 days and evaluated immune function in intestinal lymphocytes by flow cytometry in these and 4 control animals. We further collected stool samples to evaluate changes in the intestinal microbiome by 16S Illumina sequencing. Results: We observed that DRit-therapy was associated with increases in systemic inflammation as compared to controls - most notably, increased IFNg and TNFa expression from intestinal CD8+memory T-cells. Among DRit-treated RM, deep sequencing of intestinal microbiota revealed a modest but prolonged expansion of Anaeroplasmataceae and Erysipelotrichaceae which were

Poster Abstracts


232 COTRIMOXAZOLE MODULATES IMMUNE CELL ACTIVATION & THE GUT MICROBIOTA IN HIV INFECTION Claire D. Bourke 1 , Ethan K. Gough 2 , Chipo Berejena 3 , Mutsa Bwakura- Dangarembizi 3 , Joseph Lutaakome 4 , Adeodata Kekitiinwa 5 , Victor Musiime 6 ,


CROI 2019

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