Cytotoxicity of anti-beta 2-microglobulin xenoantisera to human and murine myeloid progenitor cells and lack of cross-reactivity with colony-stimulating activity.
A previous report has suggested an antigenic relationship between beta 2-microglobulin (beta 2 mu) and granulocyte colony-stimulating activity (CSA). Since human myeloid progenitor cells (CFU-C) express HLA antigens and beta 2 mu is a known molecular component of HLA antigens, we wondered whether the reported effect of anti-beta 2 mu heteroantisera on in vitro granulopoiesis might result from cytotoxicity to CFU-C rather than from cross-reactivity with CSA. To test this, we used rabbit antibody reactive with human and murine beta 2 mu (anti-beta 2 mu). Treatment of human and murine bone marrow cells with anti-beta 2 mu and complement resulted in 95+% inhibition of CFU-C colony formation compared to controls. To test for an effect on CSA, anti-beta 2 mu was incubated with human and murine sources of CSA. After addition of goat anti-rabbit Ig antiserum to precipitate immune complexes and unbound anti-beta 2 mu, the supernatant fluid retained CSA but was no longer cytotoxic to CFU-C. These results indicate that human and murine CFU-C express membrane beta 2 mu and that anti-beta 2 mu antibody does not cross-react with human or murine CSA.
D000818:Animals; D001609:Beta-Globulins / Q000276:immunology*; D001854:Bone Marrow Cells; D003114:Colony-Forming Units Assay; D003115:Colony-Stimulating Factors / Q000494:pharmacology; D003429:Cross Reactions; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D001613:beta 2-Microglobulin / Q000276:immunology*
D001609:Beta-Globulins; D003115:Colony-Stimulating Factors; D007106:Immune Sera; D001613:beta 2-Microglobulin