IL-12 enhanced the cytolytic function of zoledronate-expanded TCR/Vγ9Vδ2 cells from peripheral blood of breast cancer patients

Abstract

Background: In a series of preclinical studies, we have reported that IL-12 can enhance the phenotype and functionality of CD8+ T cells during their in vitro expansion for anti-cancer adoptive T cell therapy (ACT). Vγ9 +Vδ2+ T cells can be used in ACT since they are expanded and activated upon their stimulation with aminobisphosphonates such as zoledronate (ZOL). Aim: We aimed in this study to utilize IL-12 to enhance the expansion and functions of ZOL/ IL-2-expanded Vγ9 +Vδ2+ T cells as well as CD8+ T cells from breast cancer patients in comparison to healthy control subjects upon the condition in vitro. Materials and Methods: Peripheral blood mononuclear cells (PBMCS) were separated from healthy donors (HD) and stage II breast cancer patients (BCII). PBMCs were cultured (1x106 cells/mL) in a complete RPMI medium, and treated with combinations of ZOL+IL-2, ZOL+IL-2+IL-12 or IL-2+IL-12. Cultured cells were harvested on days 7 and 14 of culture and their phenotypic analysis and cytolytic function were performed by flow cytometry. Results: The addition of IL-12 during expansion by ZOL+IL-2 promoted the responsiveness of expanded Vγ9+Vδ2+ T cells from breast cancer patients significantly as ZOL+IL-2 effect. Interestingly, ZOL+IL-12+IL-2 induced a robust granzyme B (GZB) and perforin (PER) production from Vγ9+Vδ2+ at D7 of the stimulation. Conclusion: ZOL+IL-2+IL-12 effect on cytolytic activity from Vγ9+Vδ2+ was instantly at D7 and gradual increase of CD8+ cytolytic activity at D14. Which supported a balanced activation level during the expansion process.