Antigen-specific murine CD8+ T cells acquire an effector phenotype following treatment with immobilized CCL21 and ICAM1, leading to enhanced tumor suppression abilities
2Bioinformatics Unit, Department of Life Sciences Core Facilities, Weizmann Institute of Science, Israel
3Department of Systems Immunology, Weizmann Institute of Science, Israel
Tumor infiltrating lymphocytes (TILs) can be extracted from resected tumor tissues, expanded ex vivo and re-infused into the patient, where they often display beneficial therapeutic effects. That said, a major limitation in the implementation of TIL-induced therapy resides in the difficulty in achieving rapid and efficient expansion of T cells, while retaining their functionality.
In recent years, our group developed a biomimetic "synthetic immune niche" (SIN) technology, based on culturing activated T cells on surfaces coated with CCL21 and ICAM1. This engineered SIN was shown to augment the expansion and survival of CD4+ T cells and increase the number and antitumor activity of cytotoxic CD8+ T cells. In the current project, we explored the cellular and molecular mechanisms underlying these activities. Towards that end, we have performed multiparameter immunophenotyping and molecular profiling of untreated or SIN-treated CD8+ T-cells.
Cellular profiling, using spectral flow cytometry, showed that SIN-induced enhancement of killing capacity, is associated with a major increase in the cellular levels of T cell proliferation and cytotoxicity markers, as well as a shift toward an effector memory cell phenotype. Consistent with flow cytometry data, molecular profiling revealed that CCL21+ICAM1 signaling induced upregulation of T-cell proliferation and cytotoxicity related genes and downregulation of proapoptotic and exhaustion associated genes. Taken together, this study suggests that the integration of cellular and molecular profiles provides new insights into the mechanism underlying the collective effect of CCL21+ICAM stimulation on T cells.