CHARACTERIZATION OF A NOVEL ANTI-CD19 CAR CONSTRUCT CO-EXPRESSING THE COSTIMULATORY MOLECULE GITRL

• DOI: 10.1016/j.htct.2023.09.2359
• Publication Date: 2023-10-18T17:27:05Z
• Authors: DMC Fantacini; SCG Lima; R Rossetti; IP Furtado; RM Silveira; L Tsyrenov; H Shiku; DT Covas; LEB Souza
• Keywords: 03 medical and health sciences; 0302 clinical medicine; Diseases of the blood and blood-forming organs; RC633-647.5

Adoptive therapy using Chimeric Antigen Receptor T-cell (CAR-T) technology has emerged as a groundbreaking immunotherapeutic approach for treating various hematological malignancies. Among the diverse CAR-T targets, CD19, B-cell surface marker, demonstrated remarkable success in However, despite impressive clinical outcomes, challenges such efficacy and insufficient vivo persistence still exist. To address these limitations, preclinical investigations are exploring integration of additional co-stimulatory molecules into CAR constructs to enhance effector functions persistence. GITRL (Glucocorticoid-Induced TNF Ligand) belongs family is type II transmembrane protein. The interaction between Glucocorticoid-Induced Tumor Necrosis factor (GITR) its Ligand (GITRL) reverses regulatory T cell suppression, leading enhanced immunity against tumors. Therefore, goal this research was develop validate novel targeting incorporating domain construct. Initially, peripheral blood mononuclear cells (PBMCs) from healthy donor were activated with CD3/CD28 beads transduced lentiviral particles an MOI (multiplicity infection) 5. Subsequently, frequency expressing anti-CD19 or CAR-GITRL determined by flow cytometry, resulting 52.4% 64.9% CAR+ cells, respectively. then assessed their ability recognize selectively eliminate CD19-expressing cancer vitro cytotoxicity assays. Both CAR-GITRL-T exhibited potent killing CD19-positive target lysis percentages 92.65%±0.01% 84.31%±0.01%, In contrast, non-transduced showed minimal no activity eliminating cells. Importantly, cytotoxic remained strong even upon re-challenge, elimination 78.75%±0.08% 63.23%±0.17% These findings suggest that did not demonstrate exhaustion, contributing durability therapeutic effect. evaluate antineoplastic potential generated we established disseminated lymphoma model intravenously injecting Raji luciferase immunodeficient mice. After six days tumor infusion, animals treated cellular suspensions containing suboptimal dose 2.5×106 200 μL PBS (n = 5). A control group received only 6). 22 treatment, all had be euthanized due hind limb paralysis caused infiltration loss at least 20% initial body weight. Conversely, bioluminescent signal analyses groups reduction burden 83.8% 93%, This significant highlighted administered effect translated extended survival groups, which monitored 36 post-treatment (p < 0.0001, Log-rank test). there differences observed groups. conclusion, study underscores molecule CD19-targeted therapy. Further warranted elucidate mechanisms underlying positive outcomes optimize utilization tool neoplastic diseases.