The TCR Vβ repertoire usage of T-cells from cord blood induced by chronic myelogenous leukemia associated antigen

Abstract

Understanding the clonality and restricted usage of the TCR Vβ repertoire of expanded T-cells induced by the chronic myelogenous leukemia (CML) associated antigen may be useful in helping design new immunotherapeutic strategies specifically for CML. T-cells from cord blood that had been stimulated by different stimulators (IL-2, PHA, CML cells, K562 cells and bcr-abl peptide) were amplified in vitro by liquid T-cell culture and the mixed lymphocyte and tumor cell culture (MLTC) method. By using the RT-PCR, the CDR3 segments of 24 variable region genes of TCR β was analyzed in T-cells from 22 cases of cord blood before and after T-cell culture, to observe the usage of TCR Vβ repertoire. The PCR products were further labeled with fluorescence and analyzed by the Genescan technique for the CDR3 size, to evaluating clonality of the detectable TCR Vβ T-cells. Only a part of 24 Vβ subfamily T-cells (3–15 subfamilies) could be detected, however, all of the 24 TCR Vβ subfamily of T-cells were detected after in vitro culture with PHA or IL-2+anti-CD3 antibody. The number of expressed TCR Vβ subfamilies was gradually reduced by prolonging the time of culture with CML-associated antigens. The restricted expression of TCR Vβ subfamilies and oligoclonal expansion of Vβ21 T-cells were found in cultured T-cells induced by CML cells, K562 cells or bcr-abl peptide. In conclusion, T-cells from cord blood may have the potential capability of proliferation in different TCR Vβ subfamily T-cells, and the ability for restricted expression and clonal expansion, when T-cells were induced by CML associated antigen.