CROI 2024 Abstract eBook

Abstract eBook

Poster Abstracts

441

A Skewed NK Cell Repertoire Persists in People With HIV-1 Despite Long-Term ART Renee R Anderko 1 , Allison E. DePuyt 1 , Rhi Bronson 1 , Arlene C. Bullotta 1 , Evgenia Aga 2 , Ronald J. Bosch 2 , R. Brad Jones 3 , Joseph J. Eron 4 , John W. Mellors 1 , Rajesh T. Gandhi 5 , Deborah K. McMahon 1 , Bernard Macatangay 1 , Charles R. Rinaldo 1 , Robbie B. Mailliard 1 1 University of Pittsburgh, Pittsburgh, PA, USA, 2 Harvard TH Chan School of Public Health, Boston, MA, USA, 3 Weill Cornell Medicine, New York, NY, USA, 4 University of North Carolina at Chapel Hill, Chapel Hill, NC, USA, 5 Massachusetts General Hospital, Boston, MA, USA Background: HIV-1 infection can greatly impact the NK cell phenotypic and functional repertoire. This is highlighted by the expansion of a rare population of FcRγ–NK cells exhibiting adaptive immune characteristics in people with HIV-1 (PWH). While current antiretroviral therapy (ART) effectively controls HIV-1 viremia and disease progression, its impact on HIV-associated NK cell abnormalities remains unclear. Methods: We performed a 4-year longitudinal analysis characterizing conventional and memory-like NK cells from PWH (n=60) participating in the AIDS Clinical Trials Group (ACTG) A5321 study, all of whom initiated ART in ACTG trials during chronic infection and had well-documented consistent HIV-1 suppression. Peripheral blood mononuclear cells collected at 4 weeks, 1 year, and 4 years post-initiation of ART were characterized. The phenotypic and functional profiles of NK cells, as well as frequencies of FcRγ−NK cells, were determined by flow cytometry analysis at baseline and following a 24h exposure to rhIL-18 (500 ng/ml) and rhIL-12p70 (50 ng/ml). Plasma CMV/EBV IgG antibody titers were measured by ELISA, and CMV/EBV viremia was determined by real-time qPCR. The BD Rhapsody TM Express System was used for single-cell multiomic analysis. Results: Throughout the first 4 years of ART, a skewed repertoire of highly specialized antibody responsive but rhIL-18/IL-12 unresponsive FcRγ– memory-like NK cells persisted. This was accompanied by an increase in both CD57 and KLRG1 expression and a decrease in NKp46 within the total NK cell population, indicative of a progressive differentiation toward senescence. These characteristics were linked to increasing antibody titers to CMV, with CMV viremia detected in 35% and 29% of PWH at years 1 and 4 of ART. Interestingly, 40% of PWH displayed an atypical NK cell subset distribution based on differential expression patterns of CD56 and CD16. Single-cell multiomic trajectory analysis (Figure) revealed that these abnormal subsets likely represent intermediate stages of NK-poiesis, a phenomenon partially corrected between 1 to 4 years of ART. Conclusion: Our findings indicate that HIV-associated NK cell irregularities persist in PWH despite long-term, effective ART. This underscores the need to better understand the causative mechanisms contributing to these immune irregularities. The study also provides a rationale for exploiting in HIV remission trials the selectively expanded antibody responsive FcRγ–NK cells that are maintained in PWH during ART.

investigated. We hypothesized that trained monocytes, as induced by b-glucan, are crucial in orchestrating a beneficial antiviral immune response associated with long-term spontaneous HIV control. Methods: 1895 people living with HIV, among which 114 HIV controllers (HIC) classified as Elite controller (EC), viremic controllers (VC) and transient controllers (TC), were included (2000HIV study - NTC03994835). First degree family members (FAM) of HIV controllers and non-HIV controllers (non-HIC) were part of the 2000HIV-trained study (NCT04968717). We analyzed multi omics data consisting of: 1) cytokine/chemokine production upon stimulation, 2) circulating concentrations of b-glucans, 3) trained immunity induction through the exposure of monocytes to b-glucan and restimulation with LPS, 4) genome-wide association study (GWAS), 5) single-cell and bulk RNA seq expression in PBMCs, 6) epigenomic profile using H3K4me3 ChiP- and ATAC- seq. Results: Monocytes of HIC and their FAM showed increased production of IL-1b, IL-6 and MCP-1 upon viral and bacterial stimulation compared to non-HIC and their FAM, respectively. Difference in monocytes responsiveness was stronger in ECs but not different between TCs and non-HIC. b-glucan induced trained immunity responses in all groups, yet upregulation of TNF and IL-6 production was highest in HIC and their FAM. Genetic data (GWAS) showed no link between SNPs associated with HIV control and monocyte responsiveness of HIC. Interestingly, HIC and their relatives displayed higher circulating concentrations of b- glucan, suggesting a trained phenotype in their monocytes. scRNA-seq demonstrated that monocytes of HIC displayed upregulation of type I IFN and antigen processing and presentation genes, as well as downregulation of genes associated with chronic inflammation and regulation of DNA transcription. Moreover, changes in gene expression levels and cytokine production of HIC, more prominently in EC, were sustained by changes in chromatin accessibility in innate immune genes, among which NF-kB and type I IFN were reported. Conclusion: Monocyte responsiveness is increased in HIV controllers and their relatives, which is associated with trained immunity and related epigenetic regulation. These traits are stronger in EC compared to transient controllers, suggesting the importance of a trained program in monocytes in maintaining HIV control. The figure, table, or graphic for this abstract has been removed. Effective Elimination of HIV-1 Infected CD4+ T-Cells by NKG2C+ “Memory-Like” NK Mediated by Trail Ildefonso Sánchez 1 , Marta Calvet Mirabent 1 , Olga Popova 1 , Ignacio de los Santos 1 , Lucio J. García- Fraile 1 , Ilya Tsukalov 1 , Arantzazu Alfranca 1 , María Buzón 2 , María A. Muñoz-Fernández 3 , Francisco Sánchez- Madrid 1 , Enrique Martín-Gayo 4 1 Hospital Universitario de La Princesa, Madrid, Spain, 2 Hospital Universitario de la Vall d’Hebron, Barcelona, Spain, 3 Hospital General Universitario Gregorio Marañón, Madrid, Spain, 4 Universidad Autónoma de Madrid, Madrid, Spain Background: "Memory-like" NKG2C+ Natural Killer (NK) cells from people with HIV-1 (PLWH) induced in the presence of dendritic cells (DC) are associated with a more effective elimination of autologous latently HIV- 1 infected CD4+ T cells. TRAIL is a TNF family receptor that can induce cytotoxic function. In this study, we evaluated the expression of this receptor and its potential role in function of memory-like NK cells eliminating HIV-1 infected CD4+ T cells. Methods: NK cells were isolated from the blood of n=19 PLWH on ART and activated in the presence of autologous monocyte-derived DC pre-treated with nanoparticles loaded poly I:C (Nano-PIC DC). Expression of TRAIL in different memory and effector NK cell subsets defined by NKG2C vs CD57 expression was tested and associated with functional ability to kill HIV-1 infected cells. In addition, expression of the TRAIL ligand DR4 was also tested in PHA+IL-2 reactivated p24+ isolated CD4+ T cells. Finally, impact of anti-TRAIL, anti- NKG2C and anti-NKG2D or isotypic mAbs in NK cell-mediated elimination of p24+ HIV-1 infected CD4+ T cells from PLWH was tested in the presence of Romidepsin and Raltegravir. Results: CD56dim and CD56- CD16+ NK cells from PLWH exposed to nano-PIC DC displayed increased levels of TRAIL compared to cells stimulated with control nano DC (p=0.0039). Induction of TRAIL expression was higher in CD56dim and CD56- CD16+ NK cells from PLWH characterized by effective elimination of infected CD4+ T cells at baseline (p=0.0076; p= 0.0133) and after activation with nano-PIC DC (p=0.0076; p= 0.0133), respectively. Notably, higher levels of TRAIL were enriched in NKG2C+ cells from good compared to bad PLWH responders after nano-DC stimulation. Moreover, TRAIL was enriched in NKG2C+ CD57- NK cells, compared to NK cells expressing CD57 (p=0.0391). In this regard, TRAIL negatively associated with expression of TIGIT in CD56dim CD16+ NK cells

Poster Abstracts

443

442

Trained Immunity in Monocytes Is Associated With Persistent Elite Controller Status Jessica dos Santos 1 , Suzanne Ruijten 1 , Albert L. Groenendijk 2 , Nadira Vadaq 1 , Rainer Knoll 3 , Rob t. Horst 1 , Marc Blaauw 1 , Louise E. van Eekeren 1 , Wilhelm A. Vos 1 , Victoria Rios-Vazquez 1 , Vasiliki Matzaraki 1 , Jan van Lunzen 1 , Leo Joosten 1 , Mihai Netea 1 , Andre J. van der Ven 1 1 Radboud University Medical Center, Nijmegen, Netherlands, 2 Erasmus University Medical Center, Rotterdam, Netherlands, 3 University of Bonn, Bonn, Germany Background: The protective role of trained innate immunity in various infections is well known, but its impact on HIV control has not been

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