Modulation of the Immune Response by Plasma Protease Inhibitors.

Abstract
In two different cytolytic assays, dose-dependent inhibition of antibody-dependent cellmediated cytotoxicity and natural killing by alpha2-macroglobulin (α2m) and its subunits was observed. α2m subunits were approximately four times more inhibitory in both assays than the native 2m molecule on a molar basis. Analysis of trypsin protein esterase activity demonstrated that α2m subunits were four times more active than the parent molecule.