CROI 2020 Abstract eBook

Abstract eBook

Poster Abstracts

first year of infection. Furthermore, CD16– monocytes showed significantly higher levels of Siglec-1, suggesting that CD16+ and Siglec-1+monocytes were activated by different pathways. Conclusion: Early monocyte activation and plasma IFN-a levels showed similar dynamics during PHI. In contrast, CD16 expression significantly increased after 6 months of infection and was uncoupled from plasma sCD14 and sCD163 levels. Considering the role of activated monocytes in cardiovascular disorders and aging of the innate immune system, an early treatment may potentially reduce monocyte activation, resulting in long-term clinical benefit. 260 IMMUNOLOGICAL AND CYTOKINE CHANGES IN BLOOD AND GUT MUCOSA FROM PHI BY AN EARLY ART Nuria Climent 1 , Juan Ambrosioni 2 , David Nicolás 2 , M.J. Maleno 1 , L. Miralles 1 , Carmen Hurtado 1 , Marta Subirana 2 , Carmen Ligero 2 , Cristina Rodríguez De Miguel 2 , Josep Llach 2 , Michael Meulbroek 3 , Sonsoles Sánchez-Palomino 1 , Jose M. Miro 2 , Montserrat Plana 1 , for the Hospital Clínic PHI Investigators 1 IDIBAPS, Barcelona, Spain, 2 Hospital Clinic of Barcelona, Barcelona, Spain, 3 Asociación para el Transplante de Órganos a Seropositivos, Barcelona, Spain Background: The initiation of ART during primary HIV-1 infection (PHI) decreases transmission, contains viral reservoir establishment, prevents damage to immune system and reduces immune activation. The aim of this study was to analyse immunological changes in cell subsets in blood and rectal tissue as well as mucosal cytokine profile after initiating an intensified-5-drug ART regimen during very early PHI. Immunological subsets in blood (PBMC) and rectal tissue (MMC) were compared between w0 and w48 and between cases (Fiebig I-II, n=6) and controls (Fiebig II-IV, n=11) by multi-parametric flow cytometry. The analysis of 25-cytokines on rectal fluid was performed using Luminex assay. Clinical Trials NCT02588820. Results: At w48, all except one patient in the controls have undetectable plasma VL. At w48, a higher increase of blood CD4+ T cells was observed in cases (from 39.05% to 47.47% p=0.031) than in controls (from 36.50% to 36.10%, p>0.05). CD4/CD8 ratio was also higher in cases both in PBMCs and in MMCs. ART highly decreased activated CD8+ T cells in both cases (from 24.3% to 12.6%, p=0.0313) and controls (from 30.1% to 7.5%, p=0.004) from PBMCs and MMCs (from 39.55% to 22.80% in cases, p=0.0087 and from 52.8% to 36.9% in controls, p=0.004). Concerning naïve CD4+ and CD8+ T cells, higher percentages were seen in cases with respect to controls even before initiation of ART and were maintained at week 48. Moreover, CD8+ TSCM cells were higher in cases before and after ART (p=0.014 and p=0.005, respectively). At mucosal tissue, percentage of macrophages (CD11c+ CD163+) was higher in controls than in cases (p=0.009) at w0 and decreased in controls (p=0.006) at w48. In general, a decrease of pro-inflammatory cytokines, such as IL-8, occurred mainly in samples from cases at w48 (721.4 vs 485.5, p=0.008). In addition, levels of Th1 (IFN-γ, IL-12, MIP-1β), Th2 (IL-4, IL-10) and Th17 cytokines and chemokines decreased similarly in both cases and controls at w48. Conclusion: An extremely early and intensified ART in PHI patients allowed good immunological reconstitution, decreased immune activation and reduced inflammatory profile in different body compartments. 261 IDENTIFICATION OF BROADLY NEUTRALIZING ANTIBODIES FROM SHIV- INFECTED CHINESE MACAQUES Nan Gao 1 , Yanxin Gai 1 , Lina Meng 1 , Chu Wang 1 , Tiejun Gu 1 , Wei Wang 2 , Xiaojun Li 3 , Thomas B. Kepler 4 , Chuan Qin 2 , Xianghui Yu5, Feng Gao 3 1 Jilin University, Changchun, China, 2 Chinese Academy of Medical Sciences, Beijing, China, 3 Duke University School of Medicine, Durham, NC, USA, 4 Boston University, Boston, MA, USA, 5 Duke University, Durham, NC, USA Background: Broadly neutralizing antibodies (bnAbs) have been obtained from HIV-1-infected individuals after 2-4 years of infection. However, bnAbs with similar breadth and potency have not been isolated from SHIV-infected rhesus macaques. Understanding how bnAbs develop in SHIV-infected non-human primates (NHPs) will have important implications in use of rhesus macaques to study efficacy of HIV-1 vaccines. Methods: Single memory B cells were sorted with a pair of HIV-1 Env V2 differentiating baits from an SHIV1157ipd3N4-infected rhesus macaque which showed broad neutralization activity in plasma after 6 years of infection. Paired variable heavy and light chains were amplified from the same B cells. Methods: Patients started an intensified ART consisting on abacavir/ lamivudine/dolutegravir regimen during 48 weeks plus darunavir-r and maraviroc the first 12 weeks. Rectoscopies were done at w0 and w48.

The recombinant IgG proteins were expressed in Expi293 cells. Neutralization activity was determined using 17 hard-to-neutralize tier-2 viruses on TZM-bl cells. Results: 48Abs were expressed and 12 of themwere found to bind HIV- 11157gp120. Six (J029, J031, J033, J038, J040 and J044) from the same lineage (VH4-2*01 F and VK1-20*01 F) neutralized 2-12 viruses. Among them, J038 and J033 had the broadest neutralizing activities, neutralizing ~70% of 17 tier-2 viruses. Both Abs also had the highest somatic mutation rate (~20%) and 18 amino acids in the HCDR3 region. Inferred UCA of the J033 lineage Abs had no neutralization activity, indicating the broad neutralization activity was obtained during the lineage maturation. No Abs from other lineages neutralized any of 17 tier-2 viruses. Epitope mapping with CAP45 mutants showed that N160A/T162A (deletion of a glycosylation site) and K169E mutants rendered the virus fully resistant to both mAbs, similar as human V2-target bnAbs. Both J038 and J033 bound deglycosylated gp120 at much reduced levels, confirming that neutralization mediated by both Abs depends on glycosylation in V2. Analysis of the viral sequences showed that the three mutations (I165L, K171R and V172A) together in V2 rendered the virus more resistant to both Abs, suggesting viruses with these mutations had escaped from this lineage of Abs. Conclusion: Similar bnAbs as those identified in humans can be elicited in rhesus macaques during natural SHIV infection. Further characterization the maturation pathway of these bnAbs by comparing to bnAbs with the similar specificities in humans will provide unprecedented insight into mechanisms of bnAb development in NHPs. Takeo Kuwata 1 , Hiroshi Ishii 2 , Saori Matsuoka 2 , Tsuyoshi Sekizuka 2 , Makoto Kuroda 2 , Shigeyoshi Harada 2 , Shuzo Matsushita 1 , Yohei Seki 3 , Hiromi Sakawaki 3 , Vanessa Hirsch 4 , Tomoyuki Miura 3 , Hirofumi Akari 3 , Tetsuro Matano 2 1 Kumamoto University, Kumamoto, Japan, 2 National Institute of Infectious Diseases, Tokyo, Japan, 3 Kyoto University, Kyoto, Japan, 4 NIH, Bethesda, MD, USA Background: Induction of potent broadly-neutralizing antibodies (bNAbs) is a key for anti-HIV vaccine development. The boosting method for B-cell maturation toward bNAb induction has not been established, although recent studies have developed germline-targeting immunogens for priming. Here, we present a unique macaque model to analyze B-cell responses leading to anti- simian immunodeficiency virus (SIV) bNAb induction. Methods: In our previous study, we obtained four rhesus macaques inducing potent anti-SIV bNAbs, VH3.33-restricted B404-class Abs, after SIVsmH635FC infection. In the present study, we examined B404-class Ab induction in six SIVsmH635FC-infected rhesus macaques. Monoclonal anti-SIV Fab clones were isolated from lymph nodes (LNs) by Bio-panning using phage display. B cell receptor (BCR) VH sequences derived from peripheral lymphocytes and LNs were analyzed by next generation sequencing (NGS). Results: B404-class Ab induction was observed in one of the six SIVsmH635FC- infected macaques but undetectable in the remaining five.Investigation of germline VH3.33 genes in five B404-class Ab inducers (one in the present study and four in the previous study) and five non-inducers revealed association of B404-class Ab induction with VH3.33 polymorphisms. Analysis of germline- reverted B404 mutants revealed that the VH3.33 residue 38 is the determinant for B404-class Ab induction. A B404-associated VH3.33 allele-positive macaque dominantly induced B404-class Abs even under undetectable viremia. Conclusion: Our results first demonstrate restriction of bNAb induction by germline VH-gene polymorphism in a macaque AIDS model. Analysis using B404-associated VH3.33 allele-positive macaques could facilitate understanding of B-cell maturation leading to potent Ab induction.

Poster Abstracts

262 VH GENE POLYMORPHISM ASSOCIATED WITH POTENT ANTI-SIV NEUTRALIZING ANTIBODY INDUCTION

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CROI 2020

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