Lymphokines secreted from sodium periodate-treated lymphocytes

Abstract

This study was designed to determine if sodium metaperiodate (NaIO 4)-treated lymphocytes secrete lymphokines and if these lymphokines are similar to those obtained from mitogen- or antigen-stimulated lymphocytes. A brief exposure of CBA spleen cells to NaIO 4 induced the secretion of significant amounts of migration inhibitory factor (MIF). This MIF had a molecular weight range between 30,000 and 58,000, and was stable when heated at 56 °C for 30 min, but unstable at 80 °C. These characteristics are similar to those previously reported for mitogen- and antigen-induced MIF. In addition, NaIO 4 induced the secretion of lymphotoxin (LT) from CBA and Balb/c spleen cells, as well as from guinea pig lymph node cells. NaIO 4 was compared to the other inducers in regard to the quantity of LT secreted. Supernatant derived from NaIO 4-treated mouse spleen cells contained less LT than supernatants derived from concanavalin A- or phytohemagglutinin-treated cells, but contained more activity than those supernatants derived from lipopolysaccharide-treated cells. CBA spleen cells secreted significantly more LT than Balb/c spleen cells after NaIO 4 stimulation. NaIO 4-stimulated CBA spleen cells secreted LT in cultures with or without serum, but stimulated Balb/c spleen cells secreted LT only in serum-containing cultures. The advantages of NaIO 4 as an inducer of lymphokines, as opposed to other mitogens or antigens, is the brief exposure of this agent to the cells after which the NaIO 4 is removed, and the lymphokines can be obtained free from the inducer.