CROI 2024 Abstract eBook

Abstract eBook

Poster Abstracts

Conclusion: Our results suggest that among virally suppressed PWH, sleep deprivation could impact systemic inflammation by activation of CD8+ T cells and macrophages. However, there is no compensatory increase in ectoenzyme expression that can increase extracellular adenosine and counteract the inflammatory process. Immunosuppressive Effects of LLDT-8 in ART-Treated SIV-Infected Rhesus Macaques Xiaosheng Liu 1 , Tingxia Lv 2 , Jing Xue 3 , Ling Lin 2 , Lianfeng Lu 4 , Xiaodi Li 4 , Yang Yang 4 , Yuanni Wu 4 , Qiang Wei 3 , Wei Cao 4 , Taisheng Li 4 1 Tsinghua University, Beijing, China, 2 Beijing Friendship Hospital, Beijing, China, 3 Chinese Academy of Medical Sciences, Beijing, China, 4 Peking Union Medical College Hospital, Beijing, China Background: Chronic immune activation plays a significant role in the pathogenesis and disease progression of human immunodeficiency virus (HIV), and the existing interventions to address this issue are limited. In a phase II clinical trial, (5R)-5-hydroxytriptolide (LLDT-8) demonstrated promising potential in enhancing CD4+ T cell recovery. However, the precise mechanism of action of LLDT-8 remains to be explored. Methods: To assess the treatment effects of LLDT-8, we conducted flow cytometry and RNA-seq analyses on eight Chinese rhesus monkeys infected with simian immunodeficiency virus (SIV). Additionally, we performed comprehensive transcriptomic analyses, including cross-sectional and longitudinal differentially expressed gene (DEG) analysis, gene set enrichment analysis (GSEA), weighted gene co-expression network analysis (WGCNA), and deconvolution analysis using peripheral blood mononuclear cell (PBMC) samples from 14-time points. These findings were further validated with RNA-seq analysis on patients who received LLDT-8 treatment, along with in vitro cellular experiments using human PBMCs. Results: Flow cytometry analysis revealed that LLDT-8 treatment significantly reduced the percentage of HLA- DR+CD38+CD8+ T cells in SIV-infected rhesus monkeys (P=0.029). The cross-sectional and longitudinal analysis identified 2531 and 1809 DEGs, respectively. GSEA analysis indicated that LLDT-8 treatment led to significant downregulation of proliferation-related pathways, such as E2F targets, G2M checkpoint, and mitotic spindle pathways. WGCNA analysis identified two modules and 202 hub genes associated with CD8 activation levels. Deconvolution analysis showed a significant decrease in the proportion of CD8+ T cells and activated CD4+ T cells during LLDT-8 treatment. Gene ontology results demonstrated that the common DEGs between LLDT-8 treated patients and rhesus monkeys were primarily enriched in cell activation and cell cycle progression. Furthermore, in vitro cellular experiments validated the consistent impact of LLDT-8 in inhibiting proliferation, activation (HLA-DR and CD38 expression), exhaustion (PD-1 expression), and IFN-γ production in human CD4+ and CD8+ T cells. Conclusion: LLDT-8 exhibited notable efficacy in alleviating immune activation in both an in vivo animal model and in vitro human cell experiments. These findings suggest that LLDT-8 may hold potential as a drug for managing systemic immune activation associated with SIV/HIV infection, warranting further prospective clinical explorati. Circulating Immunoregulatory Proteins Indicative of Poor CD4 Recovery in People With HIV on ART Preeti Moar 1 , Thomas A. Premeaux 1 , Scott Bowler 1 , Courtney Friday 1 , Sara Gianella 2 , Alan Landay 3 , Lishomwa Ndhlovu 1 1 Weill Cornell Medicine, New York, NY, USA, 2 University of California San Diego, La Jolla, CA, USA, 3 Rush University, Chicago, IL, USA Background: One-third of people with HIV (PWH) demonstrate poor CD4+ lymphocyte recovery (<200 cells/ml) despite suppressive anti-retroviral therapy (ART). Poor CD4 recovery is associated with persistent immune activation and inflammation, severe immune dysfunction, adverse comorbid outcomes, and mortality. Soluble immunoregulatory proteins and lymphocyte receptor/ligands that function in activation or inhibition are elevated in PWH, and associate with HIV-specific T cell function, HIV reservoir size, and comorbid outcomes during ART. The potential mechanism of poor immune reconstitution and relationship of poor CD4 recovery with lymphocyte-associated immunoregulatory proteins remains unclear. Here we assessed a panel of circulating immunoregulatory proteins and their association with poor CD4 recovery. Methods: Study participants enrolled in the AIDS Clinical Trials Group Longitudinal Linked Randomized Trials (ALLRT) cohort were stratified in poor CD4 recovery (CD4 <200, n=34) or CD4 count normalization (CD4 >500, n=82)

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CARD8 Activation in Myeloid Cells as a Driver of Inflammation in HIV Infection Marilia R Pinzone , Liang Shan Washington University in St Louis, St Louis, MO, USA Background: Myeloid cells play an essential role in HIV persistence and chronic inflammation. Inflammasome activation in response to "danger-associated stimuli" can lead to pyroptotic cell death and release of inflammatory cytokines such as IL-1ß and IL-18. HIV-1 protease has been shown to activate the CARD8 inflammasome in CD4 T cells, which undergo pyroptosis but do not produce IL-1ß and IL-18. We hypothesize that CARD8 can also be activated in myeloid cells upon exposure to HIV, which are poised to drive inflammation. Methods: Monocyte-derived macrophages (MDMs) were cocultured with HIV infected autologous CD4 T cells. In selected experiments, CARD8 knockout (KO) cells were used for coculture. Supernatants were collected at 8 hours for IL-1ß and IL-18 ELISA. P values were calculated using t test or ANOVA test. Results: Coculture of MDMs with autologous CD4 T cells infected with CCR5 tropic HIV isolates resulted in increased release of IL-1ß compared to uninfected cocultures(n=4, 128 vs 5 ρg/mL, p=0.02) and MDM alone (128 vs. 3.8 ρg/mL, p=0.03) at 8 hours. Similar increases were observed for IL-18. Coculture with CD4 T cells infected with X4-tropic HIV did not increase IL-1ß or IL-18 release. The release of inflammatory cytokines was prevented by pre-incubation with the caspase-1 inhibitor VX-765 or maraviroc. Coculture using CARD8 KO cells resulted in significantly lower IL-1ß (43 vs. 292 ρg/mL, p=0.03) and IL-18 (224 vs. 1384 ρg/mL, p=0.0005) levels compared to Cas9 only controls. Conclusion: Activation of the CARD8 inflammasome upon coculture with infected CD4 T cells results in release of inflammatory cytokines from autologous myeloid cells. This is abolished by CARD8 knockout as well as by use of drugs that either prevent HIV entry in myeloid cells or block the downstream signaling through caspase-1. Our findings offer novel clues into HIV pathogenesis by providing a mechanism for myeloid cell activation observed during untreated infection. Since some HIV proviruses remain translationally active even during effective antiretroviral therapy, it is possible that HIV proteins can continue to fuel inflammation by activating CARD8 in myeloid cells even when new rounds of infection are prevented. Therefore, it is important to understand whether CARD8 inhibition could decrease chronic inflammation in people living with HIV. Increased Immune Activation Following Acute Sleep Deprivation in Priya V. Borker, Benjamin Morris, Jennifer Roscher, Steven Swanger, Sanjay R. Patel, Bernard Macatangay University of Pittsburgh, Pittsburgh, PA, USA Background: Sleep disturbances are prevalent in people with HIV (PWH). The immunosuppressive adenosine (ADO) pathway is induced by inflammation and is integral in mediating homeostatic sleep drive. Dysregulation of the pathway exists in PWH. We evaluated the effects of acute sleep deprivation on the levels of immune activation and inflammation and determined whether it results in a compensatory increase in the expression of ectoenzymes responsible for extracellular ADO generation to mediate sleepiness and decrease inflammation. Methods: Twenty PWH (75% men) who have been virally suppressed on antiretroviral therapy for at least one year underwent one week of regularized sleep with at least 8 hours of opportunity to sleep each night followed by 24 hours of sleep deprivation (SD). Blood was obtained pre- and post-SD to measure levels of T cell activation (HLA-DR+CD38+), cell cycling (Ki-67+), and T-cell ectoenzyme expression (CD39; CD73) using flow cytometry. Plasma levels of soluble inflammatory markers (IL-6, sCD14, sCD163) were measured using a multiplex assay. Results: Participants had a median (IQR) age of 59.7(58.6,63.5) years and CD4 of 760(678,883) cells/mm 3 . Levels of CD8+ T cell immune activation increased post-SD (median 8.6% to 9.4%; p=0.05, paired t-test). There were no differences in CD4+ T cell activation. In contrast, cell cycling post-SD decreased in both CD8+ (88.0% to 80.8%, p=0.03) and CD4+ (90.3% to 83.5%; p=0.02) T cells. There was a trend for increased sCD163 post SD (3587 to 3838 ng/mL, p=0.08), but no differences were observed in IL-6 and sCD14. Despite increases in CD8+ T cell activation, we did not observe compensatory increases in the expression of CD39 and/or CD73 on CD8+ or CD4+ T cells. Decreased CD73 expression on CD8+ T cells post SD was associated with increased CD8+ activation (Spearman ρ= 0.76, p <0.005) and a trend toward increased CD8+ cycling (ρ=-0.43, p=0.14) but not with measures of CD4+ T cell activation (p=0.49), cycling (p=0.18) or changes in sCD14 (p=0.33), CD163 (p=0.44) or IL-6 (p=0.25).

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CROI 2024