Stimulation of leukemic myelopoiesis by P30-35 CAMAL, an inhibitor of normal myelopoiesis

CAMAL (common antigen in myelogenous acute leukemia) is an antigenic preparation isolated in this laboratory from the bone marrow or peripheral blood cells of persons with myeloid leukemias and shown in an immunoperoxidase slide test to be diagnostic of these leukemias. CAMAL has been shown to be inhibitory to myelopoiesis by normal progenitor cells in vitro. This activity is associated with material which was further purified from CAMAL preparations, and which migrates at 30-35 kDa by sodium dodecyl sulphate polyacrylamide gel electropheresls (SDS-PAGE). We now report that material from CAMAL preparations highly enriched for this 30-35 kDa material is stimulatory to in vitro colony formation by progenitor cells from patients with chronic myelogenous leukemia (CML)