Research On TCRVβ Subfamily T Clonal Cells Induced By CML Cells And Bcr/abl Peptide

Objective: To investigate the distribution and clonal expansion of TCR V P subfamily T cells in patients with chronic myelogenous leukemia (CML) and T cells from cord blood and adult peripheral blood induced by CML cells, K562 cells and bcr/abl peptide in vitro. The aim of this study was expected to provide the basic data of clonal expansion T cells with anti-leukemia effect for the specific immunotherapy eliminating minimal residual disease (MRD) in CML.Methods: Complementarity determining region 3(CDR3) size of T cell antigen receptor (TCR) 24 variable region gene was analyzed in peripheral blood lymphocytes (PBL) samples from 16 CML cases using reverse transcriptase-polymerase chain reaction (RT-PCR) and genescan techniques, to identify the distribution and clonality of TCR V P subfamily T cells. T cells from peripheral blood in a adult donor and cord blood was stimulated with CML cells, K562 cells and synthetic bcr/abl peptide and farther amplified by liquid T cells bulk culture, to induce the CML specific cytotoxic T lymphocytes. The induced T cells were performed the detection of specific cytotoxicity in CML, the phenotype identification and the distribution of clonal expansion TCR V P subfamily T cells by LDH assay, indirect immunofluorescence technique or genescan analysis, respectively.Results: All 24 TCR V P subfamily T cells were detected in ten normal cases, whereas only partial V P subfamily T cells were found in patients with CML. V P subfamily was expressed most frequently in dominant V P subfamilies, V P 1 and V P 3 were in the next place at the same time. However, individual difference was the general characteristic of dominant expression of TCR V P subfamily T cells in the patients with CML. Clonal expansion T cells could be found in some dominant TCR V subfamily T cells in 5 patients. Oligoclonal and oligoclonal tendency T cell from cord blood and adult peripheral blood could be induced bystimulate with CML cells, K562 cells and synthetic bcr/abl peptide. TCR V β 16 and V β 21 clonal expansion T cells were the commonly feature in induced T cells from different cases. Compared with CD3AK cells, most induced T cells are CD3+CD8+T cells with higher specificity and cytoxicity toward the induced cells, CML cells, but not Raji cells and K562 cells.Conclusion: Clonal expansion and dominant usage were the character of TCR V β T cells in CML patients, it may relate to the CML associated antigen. The specific cytotocity T cells for anti-CML effect could be induced by CML cells, K562 cells and synthetic bcr/abl peptide. The induced T cells which have the ability of specific cytoxicity to the CML cells may be come from the clonal expansion TCR V 3 subfamily T cells. The result would provide the basic data for the research on the specific cell immunotherapy in CML.