Tumor-Activated TCR[gamma][delta]+ T Cells from Gastric Cancer Patients Induce the Antitumor Immune Response of TCR[alpha][beta]+ T Cells via Their Antigen-Presenting Cell-Like Effects

Human [gamma][delta] T cells display the principal characteristics of professional antigen-presenting cells (APCs), in addition to playing a vital role in immunity through cytokine secretion and their cytotoxic activity. However, it is not clear whether [gamma][delta] T cells perform APC-like functions under pathological conditions. In this study, we showed that, in contrast to peripheral-derived [gamma][delta] T cells directly isolated from PBMCs of gastric cancer patients, tumor-activated [gamma][delta] T cells not only killed tumor cells efficiently but also strongly induced primary CD4 super(+) and CD8 super(+) [alpha][beta] T cells proliferation and differentiation. More importantly, they abrogated the immunosuppression induced by CD4 super(+) CD25 super(+) Treg cells and induced the cytotoxic function of CD8 super(+) [alpha][beta] T cells from patients with gastric cancer. In conclusion, tumor-activated [gamma][delta] T cells can induce adaptive immune responses through their APC-like functions, and these cells may be a potentially useful tool in the development of tumor vaccines and immunotherapy.