[Establishment of the culture system of γδ T cells in vitro and the anti-tumor effect].

Objective To establish the culture technique for culturing γδ T cells in vitro and evaluate the basic characteristics, security and anti-tumor effect of the cultured γδ T cells. Methods Phytohemagglutinin, zoledronic acid, interleukin-2 and interleukin -7 were used to induce the abundant expansion of peripheral blood mononuclear cells in vitro. Flow cytometry assay, in vitro killing assay and mouse model of human lung cancer were also adopted to assess the characteristics and the anti-tumor effect of cultured γδ T cells. Additionally, the contamination of exogenous agents and the acute toxicity of γδ T cells were determined. Results After culturing 14-16 days in vitro, the total number of γδ T cells was more than 1.0×1010. Among these γδ T cells, CD3+ γδ TCR+ cells accounted for more than 90%. None of contaminations of bacteria, fungi, mycoplasma and virus were observed. At effect target ratio (E/T ratio) of 50/1, killing efficiency of γδ T cells cultured in vitro to SK-MES-1, Ho8910, A549 and K562 reached more than 65%. In vivo experiments showed that the tumor volume of γδ T-treated mice was (828.99±61.05) mm3, significantly lower than (1 723.51±84.30) mm3 of the control mice (P<0.05). Meanwhile, no acute toxicity effect was observed in γδ T cells treated mice. Conclusion The number, purity and activity of γδT cells cultured in our institute can reach the requirement of clinical application, and the γδT cells also display strong cytotoxic activity against tumor cells such as lung cancer, ovarian cancer and leukemia. Key words: Lung neoplasms; Tumor immunotherapy; γδ T cells; Anti-tumor effect