An <i>in Vitro</i> Assay for Cellular Hypersensitivity in Man

Abstract

Abstract A reproducible in vitro assay for delayed hypersensitivity in man is described. Human blood lymphocytes from subjects exhibiting delayed hypersensitivity can be stimulated by specific antigen in vitro to produce a soluble factor which inhibits the migration of normal guinea pig peritoneal exudate cells from capillary tubes. The production by lymphocytes of this migration inhibitory factor (MIF) is immunologically specific. Nonsensitive lymphocytes are not sensitized by plasma factors to produce MIF. Some clinical applications of this in vitro assay are discussed.