801 ABSENCE OF COMMON ALL ANTIGEN ON NORMAL PLURIPOTENTIAL MYELOID, ERYTHROID AND GRANULOCYTE PROGENITORS

Abstract

The common ALL antigen (CALLA) is a unique cell surface glycoprotein detected on the lymphoblasts of most cases of childhood ALL and some B cell tumors to which Ritz et al (Nature 283: 583, 1980) have generated a cytolytic monoclonal antibody (J-5). To determine whether J-5 is distributed on the surfaces of hematopoietic progenitors and with the ultimate purpose of developing a useful approach to autotransplantation, we thrice exposed normal marrow and blood mononuclear cells to J-5 and complement after having determined that such treatment is sufficient to eradicate >99% J-5⁺ lymphoblasts. The cells were then cultured in both plasma clot and methylcellulose systems to which were added appropriate inducers. Erythroid, granuloid and mixed erythroid/granuloid colony growth was unaffected both with respect to number, size, and morphology. The normal colonies were preserved even in experiments in which J-5⁺ leukemic cells were added to the normal marrows and lysed during antibody exposure. These results suggest that CALLA is absent from the surface of committed marrow and peripheral blood myeloid progenitors. The antibody is a powerful potential tool for elimination of CALLA⁺ lymphoblasts from marrow prior to autologous bone marrow transplantation.

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account

Continue with Google

Continue with ORCiD