HUMAN ALVEOLAR MACROPHAGES AND MONOCYTES GENERATE THE FUNCTIONAL CLASSICAL PATHWAY OF COMPLEMENT IN VITRO

Publisher Website
Google Scholar
Abstract
Binding of labelled protein to EIgM kept with macrophage or monocyte cultures with 3H-leucine under serum-free conditions, shows that de novo synthesis of protein with affinity to EIgM takes place. We find that monoclonal anti-C3c and anti-C3g antibodies and polyclonal anti-C4 and anti-C5 antibodies bind to such erythrocytes. This demonstrates that C4b, C3b and iC3b are deposited on the EIgM. Additional evidence for complement synthesis is the increase in binding of anti-C4 antibodies to EIgM when the incubation time was increased from 48 to 96 hours. Stimulation of the mononuclear phagocyte cultures with ET was necessary to obtain significant amounts of erythrocyte-bound complement proteins. From these results we conclude that the functional classical pathway of complement is produced in vitro by the monocytes and macrophages.