Characterization of T-cell receptor beta chain mRNA expression in IFN-alpha-responsive chronic myelogenous leukaemia patients

Interferon-alpha (IFN-alpha) has shown promise in the treatment of chronic phase of chronic myelogenous leukaemia (CML). IFN-alpha has also been found to indirectly upregulate the expression of major histocompatibility (MHC) antigens, and to directly increase the activity of lymphocytes against tumo ur cells. To elucidate whether IFN-alpha induces anti-leukaemic activity of the autologous T cells in CML patients, we analysed the accumulation of T- cell receptor (TCR) in each V beta family using the reverse transcriptase-p olymerase chain reaction (RT-PCR) followed by single-strand conformation (S SCP) analysis. We found the predominant expression of the V beta 10, 12, an d 14 families in the peripheral blood (PB) of CML patients, in contrast to healthy donors. Especially in IFN-alpha-responsive patients, we observed an enhancement of the accumulation of the V beta 9 and 20 families, suggestin g that T cells enhanced by IFN-alpha may react with a discrete set of antig ens on the surface of malignant cells. These findings may demonstrate that CML cells possess the heterogenous antigens and the clonal expansion of V b eta 9(+) and V beta 20(+) T cells may be a prognostic indicator of the immu ne responsiveness to IFN-alpha.