Macrophage migration inhibitory factor (MIF) in guinea pigs and humans with delayed hypersensitivity.

Abstract

ABSTRACTWhen lymph node cells from PPD‐sensitive guinea pigs were incubated with PPD for 20–24 hours, they produced a soluble mediator which inhibited the migration of normal guinea pig peritoneal exudate cells (GP‐PEC) out of capillary tubes. Also, human lymphocytes stimulated by antigen produced a soluble mediator which inhibited migration of normal GP‐PEC and peripheral leukocytes.Guinea pig migration inhibitory factor (MIF) was eluted in the 34,000–67,000 molecular weight (MW) region of cultured supernatants. Human MIF was harvested from the 25,000 MW region of cultured supernatants from human lymphocytes fractionated on Sephadex G‐100. Intradermal injection of the MIF into normal guinea pigs provoked reactions characterized by erythema and induration. The histologic response was found to be similar to that induced by antigen injection into sensitized animals. MIF from antigen stimulated lymphocytes may not have species specificity between guinea pig and human, although their molecular weights are different.No correlation was found between delayed skin reactivity induced by antigen in vivo and MIF production in vitro, and it is suggested that a substance inhibitory to MIF activity may be released in the lymphocyte culture.