CROI 2025 Abstract eBook

Abstract eBook

Poster Abstracts

456

IFI16 Controls PVR and Gal-9 Expression and Its Targeting Improves Immunotherapy Against HIV-1 Marta Calvet-Mirabent 1 , Ilya Tsukalov 2 , Ildefonso Sánchez-Cerrillo 2 , Olga Popova 2 , Ignacio de los Santos 2 , Lucio Jesús Garcia Fraile Fraile 2 , Sergio Serrano Villar 3 , Santiago Moreno 3 , Francisco Sánchez-Madrid 2 , Arantzazu Alfranca 2 , Enrique Martin Gayo 4 1 Gladstone Institute, San Francisco, CA, USA, 2 Hospital Universitario de La Princesa, Madrid, Spain, 3 Hospital Universitario Ramon y Cajal, Madrid, Spain, 4 Universidad Autónoma de Madrid, Madrid, Spain Background: Stimulation of HIV-1 specific CD8+ T cells with Monocyte-derived dendritic-cells (MDDC) in an attractive immunotherapy strategy against HIV-1. However, chronic inflammation in People with HIV (PWH) has been linked to low CD4/CD8 T cell ratios, activation of the inflammasome and may affect the expression of checkpoint ligands in Mo, limiting efficacy of MDDCs. Here, we studied the impact of specific innate inflammasome sensors modulating checkpoint ligands in Mo and MDDC from PWH and their ability to activate HIV-1 specific T cells. Methods: PBMC of a total of n= 29 PWH on ART characterized by low (<0.8; LR; n=17) and normal (>1; NR; n=12) CD4/CD8 T cell ratios were recruited for the study. CD14+ Mo were isolated from PBMC and exposed to LPS or CL097 for 16h. Expression of CD40, PDL1, PVR and Galectin-9 was assessed by FACS. IL1β was analyzed in culture supernatants by ELISA. Inflammasome sensor mRNA expression was analyzed by qPCR. AIM2 and IFI16 silencing in Mo and MDDC from PWH was performed by specific siRNA and compared to cells treated with scramble controls. Finally, Caspase (Z-VAD-FMK), NLRP3 (MCC950) and AIM2/ IFI16 (ODN-TTAGGG) inhibitors were used to address modulation of checkpoint ligands in MDDC from PWH and their ability to activate polyfunctional HIV-1 Gag-specific CD8+ T cells. Results: Expression of PVR (p=0.0002) and Galectin-9 (p=0.0078) was significantly increased in CD40hi Mo from LR PWH, compared to those with NR PWH after CL097 stimulation. Also, a higher increase in IL1β secretion upon LPS and CL097 (p<0.0001) was observed in Mo from LR PWH, indicating inflammasome overactivation. While NLRP3 expression increase after stimulation was similar in all study groups, DNA sensing inflammasome sensors such as AIM2 and IFI16, were specifically either induced in response to CL097 (AIM2; p=0.0214) or basally upregulated (IFI16) in the LR PWH group. Inhibition of caspases (p=0.0195) and AIM2/IFI16 (p=0.0039) but not NLRP3 prevented upregulation of PVR in CD40hi MDDC from PWH. IFI16 silencing in Mo and MDDC from LR PWH led to a significant reduction of PVR (p=0.0156) and Galectin-9 (p=0.0391) expression upon CL097 or STING agonist stimulation. Finally, inhibition of IFI16/AIM2 by ODN-TTAGGG potentiated polyfunctional IFNg+ TNFa+ CD107a+ HIV-1-specific CD8+ T cell responses in vitro. Conclusions: IFI16 inflammasome regulates expression of ligands for checkpoint receptors and its targeting may be useful to enhance immunotherapies against HIV-1. Investigating the Effects of ADCC and CAR NK/T Cells on HIV-1 Cell-to-Cell Transmission Tanvi Mathur 1 , Alon Herschhorn 1 , Dmitrii Mazurov 2 1 University of Minnesota, Minneapolis, MN, USA, 2 Yale University, New Haven, CT, USA Background: Despite the success of antiretroviral therapy in controlling HIV-1 replication, achieving a cure remains a significant challenge. One obstacle to blocking HIV-1 replication is the efficient cell-to-cell transmission (C-CT) of HIV-1, which is highly resistant to broadly neutralizing antibodies (bnAbs). Here, we studied the effects of immune-based strategies, including antibody dependent cellular cytotoxicity (ADCC) and chimeric antigen receptor (CAR) NK/T cells, on HIV-1 transmission between cells. Methods: We developed a highly sensitive assay for precise quantification of cell lysis using luciferase activity and built CAR-PBMCs based on the VRC01 and PGT121 bnAbs. We then utilized the assay to assess cellular cytotoxicity mediated by ADCC and CAR-PBMCs against target cells expressing HIV-1 envelope glycoproteins (Envs). We have previously developed an ultrasensitive HIV-1 C-CT assay, using a replication-competent HIV-1 vector and an activated nanoluciferase reporter system to assess viral transmission in primary T cells. Using our nanoluciferase reporter assay, we studied the effects of a) PBMCs and soluble IgGs, and b) CAR-PBMCs on HIV-1 C-CT. The figure, table, or graphic for this abstract has been removed.

was insufficient to significantly reduce viral load compared to PBS-treated mice (q=0.43), 10-1074-Sia demonstrated superior efficacy in reducing viral load (q=0.028 compared to PBS control and q=0.05 compared to 10-1074). CD4+ T cell depletion was reduced in mice treated with 10-1074 (p=0.028) or 10-1074 Sia (p=0.08) compared to controls. Finally, while 10-1074 was unable to reduce HIV-associated inflammation, 10-1074-Sia significantly reduced HIV-induced inflammation markers such as TNFα (p=0.02), IFNγ (p=0.001), IP10 (p=0.01), and MIP1α (p=0.03). Conclusions: Conjugating sialidase to 10-1074 significantly enhanced the antibody's immune-potentiating effects, resulting in superior viral load control and improved inflammatory responses. These findings highlight 10-1074-Sia as a promising anti-HIV immunotherapeutic strategy. Further investigation into combining this approach with strategies such as shock-and-kill is warranted to explore its potential for eliminating infected cells during antiretroviral therapy.

455

Cannabidiol Has Sex-Dependent Anti-Inflammatory Effects in Long-Term Suppressed HIV-1 Adults Clémence Couton 1 , Chloé Robin 1 , Valentin Beauvais 2 , Alicia Harry 1 , Kossi Ayena 1 , Barbara De Dieuleveult 3 , Helene Klein 4 , Elodie Villalonga-Rosso 1 , Sophie Robert 2 , Laurent Hocqueloux 3 , Thierry Prazuck 3 , Lucile Mollet 1 1 Centre de Biophysique Moléculaire, Orléans, France, 2 Laboratoire d'Informatique Fondamentale d'Orléans, Orléans, France, 3 Centre Hospitalier Régional d'Orléans, Orléans, France, 4 Little Green Pharma, West Perth, Australia Background: People with long-term HIV-1 suppression (PWH) suffer from inflammaging, characterized by chronic inflammation and immunosenescence. As cannabis smokers display immune beneficial effects such as lower inflammation levels we decided to investigate the anti-inflammatory properties of one of its major component, the cannabidiol (CBD) under a full-spectrum oil, on PWH. Methods: Within the double-blind, randomized, placebo-controlled trial registered as NCT05306249 on ClinicalTrials.gov, we present herein encouraging results from the first 40 ART-treated PWH with undetectable viremia, encompassing 50% women (median time on efficient ART 20 years, median age 59-year-old). Half took 1 mg/kg twice a day of a full-spectrum, pharmaceutical grade, CBD oil for 12 weeks and the other half took a placebo medium chain triglyceride (MCT) oil. On enrolment and after 12 weeks, we analyzed 34 cytokine and chemokine levels in patients’ plasma using multiplex ELISA. In 16 women and 16 men, transcriptome from CD4+ and CD14+ cells were also evaluated using BRB-seq, followed by RT-ddPCR (droplet digital PCR). Results: After 12 weeks of full-spectrum CBD, 12 out of 34 plasmatic proteins were less expressed in the whole cohort. Distinguishing the results by sex, we found that, while 12 out of 34 proteins were still downregulated in men, only 3 out of 34 were underexpressed in women. Regarding transcriptomic analyses in CD4+ cells, PWH from CBD arm displayed lower levels of pro-inflammatory cytokines. When analyzing men and women separately, 7 cytokines expression were reduced for men but only CXCL8 for women. In CD14+ monocyte transcriptome, CXCL8, IL1β, CCL3 and IL1α genes were less expressed in men whereas CCL5 was overexpressed. For women the only clear difference could be seen for the overexpressed CCL5 and underexpressed IL10. With ddPCR assays, men exhibited a lowered TNFα, IL6, IL1β and CXCL8 mRNA rate after CBD intake while only TNFα decreased in women. Conclusions: Pharmaceutical grade full-spectrum CBD oil is associated with anti-inflammatory properties regarding mRNA and proteins. This suggests that CBD could help PWH mitigate their chronic inflammation but its effectiveness varies greatly according to sex. From a global perspective, this clinical trial opens the door to investigate full spectrum CBD intake potential for other diseases associated with chronic inflammation.

Poster Abstracts

457

CROI 2025 112