CROI 2018 Abstract eBook

Abstract eBook

Oral Abstracts

18 KINETICS OF GASTROINTESTINAL DYSFUNCTION IN ACUTE SIV INFECTION OF MACAQUES Tiffany Hensley-McBain 1 , Alicia Berard 2 , Charlene J. Miller 1 , Jennifer A. Manuzak 1 , Alexander S. Zevin 1 , Patricia Polacino 3 , Brian Agricola 3 , Mark Cameron 4 , R. Keith Reeves 5 , Jeremy Smedley 6 , Shiu-Lok Hu 3 , Brandon Keele 7 , Adam Burgener 8 , Nichole Klatt 1 1 University of Washington, Seattle, WA, USA, 2 University of Manitoba, Winnipeg, MB, Canada, 3 Washington National Primate Research Center, Seattle, WA, USA, 4 Case Western Reserve University, Cleveland, OH, USA, 5 Beth Israel Deaconess Medical Center, Boston, MA, USA, 6 Oregon Health and Sciences University, Portland, OR, USA, 7 Frederick National Laboratory for Cancer Research, Frederick, MD, USA, 8 Public Health Agency of Canada, Winnipeg, MB, Canada Background: HIV and pathogenic SIV infection are characterized by gastrointestinal (GI) damage and immune dysfunction resulting in microbial translocation and immune activation, which are major contributors to non- infectious comorbidities and mortality. GI dysfunction includes damage to the epithelial barrier, loss of Th17 cells, neutrophil accumulation, microbial translocation and mucosal and systemic inflammation. However, it is unclear how and when these contributing factors occur relative to one another. Therapeutically targeting GI dysfunction requires elucidating the kinetics of these events to determine if any of these features initiates the cycle of damage. Methods: We longitudinally evaluated mucosal and systemic T cell activation, microbial translocation, immunity, and the mucosal proteome during acute SIV infection in 6 rhesus macaques challenged intrarectally with 100,000 TCID50 of SIVmac239X. Samples were collected pre-SIV and 3, 7, 14, 21, 28, 49 and 63 days post-SIV. Flow cytometry was used to assess T cell and neutrophil frequencies and activation. LPS binding protein (LBP) was measured as a marker of microbial translocation in plasma by ELISA. The colon proteome was assessed using shotgun mass spectrometry. Results: We observed early GI immune activation as evidenced by increased CD4+ T cell activation (HLA-DR) beginning 3 days post-SIV in the rectum (p=0.0312) and CD8+ T cell activation beginning 14 days post-SIV in the rectum (p=0.0312) and colon (p=0.0312). We also observed increased T cell proliferation (Ki67) 14 days post-SIV in GI tissues, and a trending increase in LBP beginning 14 days post-SIV (p=0.0625). The onset of GI dysfunction preceded peripheral and GI Th17 loss, which occurred 14-28 days post-SIV, and gut neutrophil accumulation was not observed. Proteomic analysis identified 292 proteins that were differentially regulated post-SIV, with 5% FDR for at least one time point. Hierarchical clustering of these proteins demonstrated that proteins involved in epithelial structure were downregulated 3 days post-SIV followed by an upregulation of immune proteins 14 days post-SIV. Conclusion: Overall, these data demonstrate that immune perturbations such as Th17 loss and neutrophil accumulation occur after alterations to epithelial structural protein pathways, microbial translocation, and GI T cell activation, suggesting epithelial damage and GI dysfunction occurs prior to widespread immune dysfunction. 19 PROGRESSIVE LYMPH NODE DYSFUNCTION DURING SIV INFECTION IS NOT REVERSED WITH ART Claire Deleage 1 , Ismail B. Turkbey 2 , Peter L. Choyke 2 , Yanling Liu 3 , Gregory Q. Del Prete 3 , Brandon Keele 3 , Jeffrey D. Lifson 3 , Jacob D. Estes 3 1 AIDS and Cancer Virus Program, Frederick, MD, USA, 2 National Cancer Institute, Bethesda, MD, USA, 3 Frederick National Laboratory for Cancer Research, Frederick, MD, USA Background: Initiation and maintenance of effective immune responses depends on the structural and functional integrity of secondary lymphoid tissues, particularly lymph nodes (LN). Among the fundamental biological functions of LN is the filtration of lymph and the capture of particulate antigens. To evaluate the functional consequences of progressive fibrotic damage to lymphoid tissue seen in HIV/SIV infection, we used longitudinal magnetic resonance imaging (MRI) to study uptake of a simulated particulate antigen by draining lymph nodes in SIV infected rhesus macaques (RM), and correlated these findings with histopathological analysis. We also evaluated the impact of combination antiretroviral therapy (cART) and adjunctive anti-fibrotic intervention. Methods: Four RM were infected (IV) with SIVmac239M, placed on cART (TDF/FTC/DTG) starting at 36 weeks post infection (wpi), and then treated with the anti-fibrotic drug pirfenidone started at 50 wpi continuing through 82 wpi. Longitudinal dynamic MRI scans were used to monitor and quantify

lymphatic drainage and inguinal lymph node uptake of gadolinium G5-DOTA dendrimer (~8 nm diameter simulated particulate antigen) after intradermal injection into the anterior portion of the feet. MRI was performed prior to SIV infection and at multiple time points following infection. Correlative analysis of axillary LN fibrotic damage and inflammation were performed using immunohistochemistry and quantitative image analysis. Results: We observed the rapid onset (beginning 2 weeks post infection) of LN dysfunction manifested by restricted uptake of dendrimer by inguinal LN. Persistent impaired inguinal LN dendrimer uptake correlated with histopathologic evidence of fibrotic damage in axillary LN. cART for 46 weeks, combined with 28 weeks of pirfenidone did not restore dendrimer uptake into the draining lymph nodes, and suggests that fibrotic impairment of LN function may persist for long periods of time. Conclusion: SIV, and likely HIV, infection is associated with a profound impairment of LN function due to collagen deposition, which may affect the ability to mount effective immune responses. Fibrosis may also impact tissue bioavailability of anti-viral drugs in affected sites.

Oral Abstracts

20 P38 MAPK IN VIVO INHIBITION IMPACTS SIV-MEDIATED IMMUNE ACTIVATION & CD4 T-CELL LOSS Omkar Chaudhary 1 , Felipe Lelis 1 , Ronald Veazey 2 , Anna Aldovini 1 1 Boston Children’s Hospital, Boston, MA, USA, 2 Tulane National Primate Research Center, Covington, LA, USA Background: Persistent immune activation is the hallmark of lentiviral infection in AIDS-susceptible species. p38 MAPK, activated in HIV and SIV infection, is key to induction of Interferon-stimulated genes (ISG) and inflammatory cytokines and is associated with some of the pathology produced by HIV and SIV infection in AIDS-susceptible primates. As small molecule p38 MAPK inhibitors are currently tested in human trials for other inflammatory diseases, we evaluated the effects of treating SIV-infected macaques with a p38 inhibitor, PH-797804, in conjunction with ART. Methods: Rhesus macaques were infected with SIVmac251 and divided in 6 groups: Group 1, had no treatment, Group 2, p38 inhibitor alone, Groups 3 and 5 initiated ART at week 6 or 1 after infection, Group 4 and 6 initiated ART + PH797804 at week 6 or 1 after infection. ART efficacy was evaluated by measuring viral loads and reservoirs. As primary endpoints for PH-797804 efficacy, we evaluated protein levels of selected ISG and differences in expression of surface and intracellular molecules linked to immune activation and inflammatory cytokines plasma levels. As secondary endpoints, we evaluated effects of treatment on viral loads, reservoirs, and immune system preservation. Results: ART treatment reduces viremia to very low or undetectable levels. PH797804 had no side effects, did not further reduced the viremia, and did not affect immune responses to SIV. Administered alone, it had no significant effect on immune activation. When combined with ART, numerous immune activation markers were significantly reduced compared to ART alone treatment. CD38/ HLA-DR and Ki-67 percentages in blood, lymph node and rectal CD4+ and CD8+ T cells and plasma levels of IFN-, IL-6, IL-8, and IP-10 were all significantly reduced. IRF7, pSTAT1 and IP-10 protein accumulation was also reduced. Significant preservation of CD4+/IL22+, CD4+ CM T-cells and improved ratio of Th17+/ Treg+ /CD4+ T cell was observed. After ART interruption, viremia rebounded in a similar fashion in the groups that received ART, with or without the inhibitor. Conclusion: The p38 MAPK inhibitor used here, already in clinical trials for other inflammatory diseases, significantly reduced immune activation during ART and further reduced SIV-mediated immune system deterioration. However, suppression was not complete and was approximately 65% of that of untreated animals. Residual SIV replication in tissues during ART is under investigation.

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CROI 2018