Abstract
Normal mature macrophages and granulocytes have surface membrane receptors for specific immunoglobulin and immunoglobulin complement, which can be detected by rosette formation with erythrocytes coated with antibody (EA) or with antibody and complement (EAC). There are three types of myeloid leukemic cells, IR+D+, IR+D and IRD. IR+D+ cells were induced to form receptors for EAC but not for EA by the steroid hormones prednisolone, dexamethasone and estradiol. Induction required protein synthesis and was not inhibited by cordycepin or vinblastine. Optimum induction required the continued presence of the hormones. IR+D+ cells were also induced by these hormones to migrate in agar, attach to the surface of a Petri dish and form macrophages. IR+D cells showed a lower inducibility by these hormones and no formation of macrophages. There was no induction of any of these changes with IRD cells. The steroid hormones progesterone, testosterone and cortisone did not induce these changes in any of the leukemic cells and inhibited induction by prednisolone, dexamethasone and estradiol. The results indicate that specific surface membrane changes in myeloid leukemic cells can be induced by certain steroid hormones.