Multilineage Antigen Expression and Possible Autocrine Secretion of an Interleukin 1 by Ph1-positive Leukemic Cell Line, KOPM-28

: A newly established Ph1-positive cell line, KOPM-28 was analyzed for immunological phenotype and the release of biological substance. The surface marker analysis revealed myelomonocytoid antigens, erythroid antigens and megakaryocyte-platelet antigens. Also, the cells could be induced for hemoglobin synthesis by the addition of hemin. The conditioned medium of this cell line showed the presence of interleukin 1 (IL-1) activity but not interleukin 2. Exogenous IL-1 and the conditioned medium stimulated the DNA synthesis of the cells themselves. Consequently, the yield substance works on the growth of original cells as an autocrine fashion, and might act on other normal cells as a paracrine factor.