OBJECTIVETo investigate effect of tumor-specific T cell receptor gene transfection on memory T cell differentiation in vitro.

METHODSTCRVbeta7.1 gene was transferred into peripheral blood mononuclear cells (PBMCs) obtained from healthy adults, and the expression of Vbeta7.1 was detected by flow cytometry before and after the transfection. Memory T cell differentiation was induced by stimulation with the hepatocarcinoma cell line BEL-7402 in vitro. The expression of surface molecules CD45RO, CD45RA and CCR7 was analyzed by flow cytometry to identify the phenotype and subsets of the memory T cells. Fluorescence-activated cell sorting was performed to detect the apoptosis of the tumor cells, and enzyme-linked immunoabsorbent assay was used to determine the production of interferon-gamma (IFN-gamma) for assessing the immune function of the memory T cells.

RESULTSFlow cytometry showed that TCRVbeta7.1 gene was efficiently expressed after transfection. After stimulation by the tumor cells in vitro, the expression of CD45RO in TCRVbeta7.1 gene-modified T cells increased gradually, and analysis of the coexpression of CD45RA and CCR7 revealed that the effector memory T cells constituted the majority of the differentiated memory T cells. The apoptotic rate of the tumor cells induced by the T cells increased significantly with also obviously increased INF-gamma secretion in the memory T cells.

CONCLUSIONTumor-specific TCRVbeta7.1 gene transfection can promote the differentiation of the memory T cells, the majority of which belongs to effector memory T cells that perform immune functions by inducing apoptosis and cytokine secretion.