Changes in pattern of TCR V? repertoire in peripheral blood from CML patients / 第三军医大学学报

ABSTRACT

Objective To investigate the distribution and clonality of TCR V? repertoire T cells in peripheral blood mononuclear cells with chronic myeloid leukemia(CML)at chronic phase(CP)and complete remission(CR).Methods The CDR3 of TCR V? 8 subfamily genes were amplified in mononuclear cells of peripheral blood from CML patients in CP(8 cases)and CR(8 cases)phases for observation of the usage of TCR V? repertoire by RT-PCR.The positive PCR products were further labeled with fluorescence and analyzed by genescan technique for the CDR3 size for evaluation of the clonality of the detectable TCR V? T cells.A total of 10 cases of healthy adults served as controls.Results The mean values of detectable TCR V? subfamilies were(3.25?0.89)in patients with CML-CP,predominantly in V?1,2 and V?3,whereas(3.5?0.76)of 8 V? subfamily T cells were expressed in patients with CML-CR,predominantly in V?1,2,3 and V?8.There was no significant difference between the above groups and the healthy adults(3.5?0.52).In addition,a higher frequency expression of V?8 could be found from peripheral blood in CR phase(5/8)rather than from that in CP phase(2/8)and from that of the healthy adults(3/10).Genescan analysis showed that the majority of PCR products from both CML and healthy adults displayed clonal expansion,predominantly in V?1,V?2 and V?3.Clonal expanded V?7 subfamily T cells,however,could be identified from two patients in CR phase but not in all of 10 healthy adults.Conclusion The similar distribution and clonal pattern of TCR V? repertoire T cells can be found in peripheral blood from the three groups,suggesting that the cellular immunosuppression of CML patients might not be mainly involved in the alteration of TCR V? repertoire.In CML-CR groups,the expression and clonal pattern of some V? repertoires are different from those in other groups,which needs further studies.