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 up-regulate the expression of major histocompatibility (MHC) antigens, and to directly increase the activity of lymphocytes against tumour 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 Vbeta family using the reverse transcriptase-polymerase chain reaction (RT-PCR) followed by single-strand conformation (SSCP) analysis. We found the predominant expression of the Vbeta 10, 12, and 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 Vbeta 9 and 20 families, suggesting that T cells enhanced by IFN-alpha may react with a discrete set of antigens on the surface of malignant cells. These findings may demonstrate that CML cells possess the heterogenous antigens and the clonal expansion of Vbeta 9+ and Vbeta 20+ T cells may be a prognostic indicator of the immune responsiveness to IFN-alpha.