Tumor inflating lymphocytes. Purification, expanding and cytotoxicity analisys on primary tumor cultures

Tumor Infiltrating Lymphocytes (TILs) is one of the most promising sources of autologous cytotoxic T-cells for adoptive immunotherapy, which has already shown high efficiency in the treatment of metastatic melanoma. However, the isolation of TILs from solid tumors is technically difficult. A suppressive tumor microenvironment, in particular, a high level of expression of check-point inhibitors PD-1 CTLA4, tissue hypoxia and other factors cause that T cells isolated from the tumor do not proliferate well and do not exhibit cytotoxic properties. Aims. In this study, we isolated TILs from surgical material obtained by resection of solid tumors (primary and metastatic adenocarcinomas of various localization, melanoma, glioblastoma), studied their population composition and developed protocols for the purification expanding, and activation of CD4+, CD8+ cytotoxic antitumor lymphocytes. Methods. An urgent task is the activation of TILs, turning off immunosuppressive mechanisms and increasing their antitumor cytotoxic activity...