Alpha1-Microglobulin Is Mitogenic for Guinea Pig Lymphocytes

Abstract

Guinea pig alpha1-microglobulin (alpha1-m) was found to exert mitogenic effects on guinea pig lymphocytes, i.e. peritoneal exudate lymphocytes (PEL) or T lymphocytes from regional or mesenteric lymph nodes (LNL). On the other hand, spleen T lymphocytes did not respond to alpha1-m. Stimulation of LNL required the presence of accessory cells. The stimulatory effect was strain-specific:alpha1-m clearly induced proliferation of lymphocytes from Strain 2 guinea pigs, whereas Strain 13 lymphocytes responded poorly or not at all. Moreover, alpha1-m inhibited antigen-driven proliferation of guinea pig lymphocytes. None of the effects described were species-specific, e.g. human alpha1-m exerted similar effects on the guinea pig lymphocytes. These data indicate that alpha1-m may be involved in the regulation of lymphocyte activation.