del Guercio P, del Guercio M F, Katz D H
Division of Immunology, Medical Biology Institute, La Jolla, California 92037.
Nature. 1987;329(6138):445-7. doi: 10.1038/329445a0.
Interleukin B (IL-B), formerly termed BEF (B-cell-derived enhancing factor) or IL-B4, was originally described as a non-immunoglobulin regulatory factor spontaneously produced by B lymphocytes and B-cell lines that enhances the in vitro antigen-driven antibody response of unfractionated spleen cells stimulated by thymus-dependent antigens. Since then we have examined the function of interleukin B in a number of immune reactions, both in vitro and in vivo, and found that it inhibits the activation of suppressor T lymphocytes. We report here the production of two monoclonal antibodies (mAb) that specifically inhibit interleukin B activity. The use of these mAb in the purification and characterization of IL-B is described. IL-B from both normal and transformed B cells consists of two subunits of similar size and amino-acid composition. The structure of interleukin B and its specific behaviour in biological assay distinguish it from many other known lymphokines.
