The Peritoneal Exudate Lymphocyte

Peritoneal exudate lymphocytes from guinea pigs immunized with horse radish peroxidase, dinitrophenyl guinea pig albumin, or ferritin in complete Freund's adjuvant have been shown to be significantly more reactive than other lymphocytes in two in vitro assays of cellular immune function: production of macrophage migration inhibitory factor and antigen-induced lymphocyte proliferation. The enhanced reactivity of peritoneal exudate lymphocytes cannot be accounted for by artifacts introduced by column purification or by the presence of nonlymphoid accessory cells. These observations suggest that the peritoneal exudate lymphocyte pool is a highly enriched source of cellular immune effector cells with specificity directed towards those antigenic determinants to which an animal has been recently exposed.