The feature of clonal expansion of TCR Vβ T cells from peripheral blood in patients with acute monoblastic leukemia

AIM: To investigate the distribution and clonal expansion of TCR Vβ subfamily T cells in patients with acute monoblastic leukemia (M5). METHODS: The CDR3 of TCR Vβ 24 subfamily genes were amplified in peripheral blood mononuclear cells from 9 cases with M5 using RT-PCR and the PCR products were further labeled with fluorescent and analyzed by genescan technique for the CDR3 size, to evaluate clonality of the detectable TCR Vβ T cells. RESULTS: Only 1-10 Vβ subfamily T cells were identified in M5 cases. Genescan analysis showed that oligoclonal (clonal expansion) T cells were found in some Vβ subfamilies from 8 cases with M5, Vβ 2 oligoclonal T cells were identified in six cases, whereas Vβ 7- or Vβ 9 clonal expansion T cells were detected in the other two cases, respectively. In addition, except Vβ 2, Vβ 7 or Vβ 21 oligoclonal T cells could be detected in two cases, respectively. CONCLUSION: The skew distribution and clonal expansion of TCR Vβ subfamily T cells could be found in patients with M5.It may be a specific ant i-leukemia immune response with which the host T cells were activated by the leukemia-associated-antigen.The clonal expansion T cells were tendentious in Vβ 2,which may be related to the M5 leukemia cells as sociated antigen.