Study The Inhibitory Effects Of CD3~+CD4~-CD8~-T(DNT)Cells On Prostate Cancer Growth In Vivo And Expansion Of Dnt Cells In Vitro

The immune cell therapy is an emerging therapeutic approach, which assist to develop anti tumor immune systems in cancer patients. The CD3+CD4-CD8-T (double negative T cells, DNT) cell is one of novel target cells in immune cell therapy. The purpose of this study is to observe the inhibitory effects of DNT cells on Prostate cancer growth in vivo and investigate the expanding of DNT cells in vitro.Main approaches of this study are:first, establish a tumor-burdened SCID mouse model:the SCID mice were randomly divided into3groups, and were administrated different number of PC-3cells through subqutaneous injection. Secondly, DNT cells were isolated from human peripheral blood cells by using Rosettesep antibodies adsorption method. The cells were purifed by using Easysep immune magnetic beads after amplification. The purity of DNT cells was measured by flow cytomertry. Third, test the inhibitory effects of DNT cells on growth of Proststic cancer in mice. The SCID mice were injected DNT cells at the time the tumor growth to0.3cm x0.3cm, by tail vein injection. PBS and CD8+T cells were used as control. After injection, we monitored the weight and general state of mice and measured the tumor volume every4days. We sacrifieced mice at week4, and collected the tissue. We analyzed the rate of tumor inhibition based on the weight of mass.Our research results showed that the subcutaneous injection of0.5×106Prostate cancer cells can successfully develop non hormone-dependent tumor-burdened SCID mouse model. The purity of DNT cells is above98%after purification. The tumor inhibitory rate of DNT cells was42%,and CD8+T cells was33%.In coculsion, SCID prostate cancer animal model can be established by injecting PC-3cells (0.5×106). we successfully amplified the DNT cells in vitro,and these amplified DNT cells had inhibitory effect to tumor growth in prostate cancer animal model. Our results provide the basis for further study of the mechanisime of DNT cells in malignant tumor immune regulation and the theoretical basis for clinical application in the future.