HLA-DR1-RESTRICTED BCR-ABL (B3A2)-SPECIFIC CD4(-LYMPHOCYTES RESPOND TO DENDRITIC CELLS PULSED WITH B3A2 PEPTIDE AND ANTIGEN-PRESENTING CELLS EXPOSED TO B3A2 CONTAINING CELL LYSATES() T)

Chronic myeloid leukemia (CML) is characterized by a specific transloc ation of the c-abl oncogene on chromosome 9 to the break point cluster region (bcr) on chromosome 22, t(9;22) (q34;q11). This translocation results in the expression of a 210-kD bcr-abl protein fusion gene prod uct. The juxtaposition of the bcr and abl genes produces a novel junct ional amino acid sequence, which may be presented by antigen-presentin g cells and recognized specifically by human T lymphocytes, We have ge nerated a CD4(+) T lymphocyte line (NG-1) which recognizes the peptide epitope (GFKQSSKALQR) in association with HLA-DR beta 10101-02, A co mparison of antigen-presenting cells showed that CMRF-44(+) blood dend ritic cell presented a 12mer b3a2 peptide effectively, The b3a2 peptid e was able to generate specific primary T-lymphocyte responses in othe r HLA-DR1 donors. We also show that bcr-abl, b3a2 peptide-specific T-l ymphocyte lines proliferate in response to bcr-abl b3a2 containing cel l lysates (K562 or CML PBMC derived) but not control (including b2a2 C ML PBMC) lysates. (C) 1997 by The American Society of Hematology.