Abstract: Abstract Objective To investigate the migration tendency of the expanded γδ T cells toward colorectal cancer cells. Methods Peripheral blood mononuclear cells (PBMCs) were isolated by density gradient centrifugation and stimulated by immobilized T cell receptor (TCR) gd specific antibody in vitro for two weeks. The expanded cells underwent immunofluorescence staining and flowcytometry analysis or flow sorting. The cytokines and chemokines expressed by gd T cell were assayed using the Bioplex 200 Suspension Array System. The chemotaxis assays were performed in the transwell chambers. Results Those in vitro-expanded γδ T cells primarily expressed chemokine receptors CCR5 and CXCR3. CCR5 and CXCR3 ligands were detected in four different colorectal cancer cell lines and in ten cases of colorectal cancer. Upon TCR engagement, expanded γδ T cells produced large amounts of Th1 and Th2 cytokines, which further increased γδ T cell accumulation. It is noteworthy that the interferon γ (IFN-γ) produced by the γδ T cells markedly increased the expression of CXCR3 ligands in colorectal cancer cells, which further boosted the migration of the expanded γδ T cells. Conculsion Our data may provide important indications for the use of adoptive γδ T cell-based immunotherapy for the treatment of colorectal cancer.

Key words: γδ T cells, Chemotaxis, Chemokine Receptor, Colorectal Cancer