Cross Reactivity of Human β 2-Microglobulin with Human Granulocyte Colony-Stimulating Activity

Abstract

Effects of antisera to human β2-microglobulin (β2m) on factors able to stimulate colony formation in culture by human granulopoietic progenitor cells were investigated. The colony-stimulating activity (CSA) present in media conditioned by cultures of human peripheral leukocytes was suppressed by treatment with anti-β2m. This inhibition was not due to a direct effect on the granulopoietic progenitor cells; controls to test for cytotoxicity and for noncytotoxic inhibition of the progenitor cells by anti-β2m yielded negative results. These experiments provide evidence for a relationship between human CSA and β-microglobulin, and suggest a possible analogy between molceules involved in the in vitro regulation of granulopoiesis and products of the major histocompatibility gene complex.