INDUCTION OF CELL-ASSOCIATED INTERLEUKIN-1 THROUGH STIMULATION OF THE ADHESION-PROMOTING PROTEINS LFA-1 (CD11A/CD18) AND CR3 (CD11B/CD18) OF HUMAN MONOCYTES

Serum‐free culture of human monocytes in the presence of monoclonal antibodies to the LFA‐1 α chain (CD11a), CR3 α chain (CD11b) or β chain (CD18) bound to Sepharose induced the dose‐dependent production of cell‐associated interleukin (IL) 1 activity and of IL 1α and IL 1β antigens, but no release of extracellular IL 1 activity or antigen in the culture medium. Triggering of IL 1 production was also observed with insolubilized anti‐CD11/CD18 F(ab')2 antibodies. Two cross‐linked antibodies recognizing distinct epitopes on the CD11b molecule induced cell‐associated IL 1. Soluble antibodies did not induce IL 1 production. The kinetics of induction of IL 1 by stimulation of adhesion‐promoting proteins differed from those of IL 1 induction by adhesion to plastic. The lack of induction of IL 1 release by stimulation of the CD11/CD18 molecules resembled the intracellular accumulation of IL 1 induced by lipid A. Induction of IL 1 by adhesive processes may be a mechanism by which T cells trigger IL 1 production by monocytes during antigen presentation. Copyright © 1990 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim