CROI 2018 Abstract eBook

Abstract eBook

Poster Abstracts

213 INFLAMMATORY MONOCYTES CONTRIBUTE TO IMPAIRED INFLUENZA VACCINE RESPONSES IN AGING Varghese George , Suresh Pallikkuth, Rajendra Pahwa, Lesley R. de Armas, Stefano Rinaldi, Margaret Roach, Li Pan, Maria F. Pallin, Celeste Sanchez, Margaret Fischl, Gordon Dickinson, Allan Rodriguez, Maria L. Alcaide, Savita Pahwa University of Miami, Miami, FL, USA Background: Influenza vaccine responses are often impaired in old age and in HIV infection despite virologic control with ART but innate immunologic determinants are not well understood Methods: Virologically suppressed HIV+ (n=139) and healthy control (HIV-, n=137) participants classified by age as young (Y,19-39yr), middle-aged (M,40-59yr) and old (O,≥60) were evaluated for monocyte- and NK cell subsets by flow cytometry pre- and post-influenza vaccination. Group comparisons and correlations with age, HIV infection and influenza Ab titers were determined by the Mann-Whitney and Spearman test respectively Results: At pre-vaccination, mean frequencies of inflammatory monocytes (IM, CD14+CD16+) calculated as a percent of total monocytes (LiveCD45+CD3- CD56-HLADR+CD14+) were significantly higher in O and M compared to Y in both HIV+ (O,1.5%,M 1.1%,Y 0.4%) and HIV- (O 1.8%,M 0.9%,Y 0.5%). Among HIV+ integrin α (CD11b) expression on IM was also highest in O (MFI, O 1884, M 1250, Y 1150). Overall, CD11b MFI on IM correlated with age (r=0.17, p=0.03), CC chemokine receptor-2 MFI (CCR2,r=0.30,p=0.002) on IM and plasma levels of soluble Tumor Necrosis Factor Receptor-1 (sTNFR1,r=0.6,p=<0.0001), and exhibited inverse correlation with post-vaccination influenza H1N1 antibody titers (r=-0.24,p=0.0003). When HIV+ participants were divided based on IM CD11b MFI into CD11bhi (MFI>1961) and CD11blow (MFI<533), those with CD11bhi IM showed higher plasma sTNFR1 (1381 vs 1042pg/ml,p=0.003) higher monocyte CCR2 MFI (3650 vs 2719,p=0.001) and lower post-vaccination serum Ab titers at d7 (HAI titer 366 vs 695, p=0.03) as well as d28 (440 vs 896, p=0.02). FACS sorted purified IM from CD11bhi versus IM from CD11blow expressers also showed higher CXCL-10 (log¬2 expression,37 vs 33,p=0.03) and LPS stimulated secretion of TNFα (1098 vs817pg/ml,p=0.05) and IL-6 (1586 vs 957 pg/ml, p=0.05) in culture supernatants. In HIV+ CD11bhi IM expressers, antigen-specific CD4 T cell proliferation by Cell Trace dye dilution assay was greater in PBMC depleted of IM compared to total PBMC (6.1%vs 3.1%,p=0.05). Among NK cells (LiveCD45+CD3-CD14-CD56+) terminally differentiated subset (CD56loCD16hi) was higher in HIV+ compared to HIV- in all age groups at pre- vaccination but did not correlate with vaccine responses. This NK cell subset or CD11b+ IM did not change post-vaccination Conclusion: CD11bhi inflammatory monocytes are exacerbated with aging in HIV+ and negatively impact immune function involved in Ab response to influenza vaccination 214 TRANSCRIPTOME PROFILING AND DATA MINING: PREDICTIVE GENES OF HIV DISEASE PROGRESSION Francisco Diez Fuertes 1 , Esther Calonge 2 , Maria Pernas 2 , Humberto Erick De La Torre Tarazona 2 , Isabelle Casademont 3 , Anavaj Sakuntabhai 3 , José Alcamí Pertejo 2 1 Institute de Salud Carlos III, Majadahonda, Spain, 2 Institute of Health Carlos III, Madrid, Spain, 3 Institute Pasteur, Paris, France Background: The elite controller (EC)-long term non-progressors (LTNP) represent a spontaneous model of activation of the immune system against HIV-1, maintaining high levels of CD4+ T cell counts and undetectable viral replication in the absence of antiretroviral therapy (ART). The use of transcriptome studies combined with data mining reveals potential markers of HIV disease progression. Methods: Peripheral blood mononuclear cells transcriptome of 30 HIV-infected individuals were sequenced in a HiSeq2000 System (Illumina), including 8 EC-LTNPs, 8 viremic LTNPs (vLTNP) and the same 7 typical progressors before (preTP) and after (postTP) receiving ART. The predictive model of disease progression was created combining the transcript abundance estimation obtained from Cufflinks with a bias-corrected feature selection procedure based in leave one out cross-validation and a hierarchical Bayesian classification. Error rate (ER) and the average of minus log predictive probabilities (AMLP) at the true value were used to evaluate the optimal selection of predictive

genes. A final classification model was build, obtaining the probability for each individual to be classified as EC-LTNP, vLTNP, preTP and postTP. Results: A mean of 33,670,437 100 bp-reads was obtained for each library (91.7% reads mapped to the human transcriptome). The best predictive model was achieved using the abundance estimation of only 20 mRNAs among the whole transcriptome as predictive variables (ER = 0.287 and AMLP= 1.058). Ten out of these 20 genes are interferon regulated genes (IRGs), including genes related with host antiviral immune responses (HERC5, IFI44, MX1, XRCC6), target genes of P-TEFb (EPSTI1, PARP12, PARP14), ribosomal protein pseudogenes (RPL5P4, RPL4P5, RPL4P4) and eukaryotic translation elongation factor genes (EEF1G, EEF1B2, EEF1B2P3). The functional annotation of these 20 genes revealed two enriched pathways, antiviral mechanism by IFN-stimulated genes (q=0.044) and ISG15 antiviral mechanism (q=0.044). Using the estimated expression of these genes, the majority of the individuals were correctly classified (n=22, 73.3%). Conclusion: Potential markers of HIV disease progression were described combining a solid transcript abundance estimation with data mining approaches, pointing to the importance of interferon regulation in preserving high CD4+ T cell counts and HIV-1 control capacity, as well as the modification of transcription/translation machineries of cells by mechanisms that need to be investigated. 215 CD4 T CELL DEPLETION IN PRIMATES IS ASSOCIATED WITH LOSS OF INNATE LYMPHOID CELLS Joseph Mudd 1 , Kathleen Busman-Sahay 2 , Sarah DiNapoli 1 , Stephen Lai 1 , Virginia Sheikh 1 , Andrea Lisco 1 , Claire Deleage 1 , Brian Richardson 3 , David J. Palesch 1 , Mirko Paiardini 4 , Mark Cameron 3 , Irini Sereti 1 , R. Keith Reeves 5 , Jacob D. Estes 2 , Jason Brenchley 1 1 NIAID, Bethesda, MD, USA, 2 AIDS and Cancer Virus Program, Frederick, MD, USA, 3 Case Western Reserve University, Cleveland, OH, USA, 4 Yerkes National Primate Research Center, Atlanta, GA, USA, 5 Beth Israel Deaconess Medical Center, Boston, MA, USA Background: Innate lymphoid cells (ILCs) maintain mucosal barrier integrity and are depleted in HIV-1 infection. Interestingly, ILCs are not permissive to HIV-1 or SIV infection, and depletion of ILCs is not a generalized feature of all viral infections. There is thus considerable interest in understanding the exact mechanisms of ILC loss in HIV/SIV infections. Methods: IL-33R+ ILC2s and cKit+ ILC3s in gut-draining mesenteric LNs (MLNs) of SIV-, viremic SIV+ untreated, ART-treated SIV+, and SIV+ Elite Controller (EC) rhesus macaques (RMs) were assessed proportionally by flow cytometry and numerically by immunohistochemistry. To recapitulate HIV/SIV pathology in settings devoid of viral replication, MLN ILCs were assessed in SIV- RMs treated with a CD4-depleting antibody. Some of these animals received DSS, inducing low-grade endotoxemia. In addition we studied a cohort of HIV- persons with idiopathic CD4 lymphophenia (ICL), defined by CD4 counts < 300 cell/ul in the absence of any known immunodeficiency. Results: cKit+ ILC3s (capable of producing IL-17) were proportionally depleted in the acute (p=0.006, N=10) and chronic SIV+MLN (p=0.0007, N=11). cKit+ ILC3s were depleted numerically in the acute (p=0.007) and chronic (p=0.007) SIV+MLN as well . When compared to MLN ILC3 proportions in healthy animals (N=10), control of viremia was associated with reconstitution, or preservation of MLN ILC3s in ART-treated (N=6) or EC RMs (N=5), respectively. Importantly, proportions of MLN ILC3s in all animals correlated inversely with sCD14 in plasma (p= 0.008, r= -0.5). Experimental CD4 depletion in healthy RMs was sufficient to reduce MLN ILC3 percentages (p=0.03, N=2). This was observed more significantly in healthy RMs receiving anti-CD4 and DSS (p=0.0009, N=5), yet not in DSS-treated only RMs (N=2). In striking concordance to CD4-depleted healthy RMs, HIV- subjects with ICL (N=11) displayed lower numbers of blood ILC3 (p=0.0008) and ILC2 (p=0.0001). In MLNs of RMs, cKit+ ILC3s were localized to the CD4 T cell-rich paracortex, and ILC3 proportions in all SIV+ RMs correlated directly with proportions of CD4 T cells in the MLN (p=0.003, r=0.25). Conclusion: CD4 T cell loss appears to be the main driver of ILC depletion that occurs in HIV/SIV infection as it is also observed in experimental CD4 depletion in primates without SIV infection and also in patients with idiopathic CD4 lymphopenia. These data suggest that mechanisms other than direct viral replication affect ILC homeostasis in SIV/HIV infection.

Poster Abstracts

76

CROI 2018