Modulation of human neutrophil polymorphonuclear leucocyte migration by human plasma alpha-globulin inhibitors and synthetic esterase inhibitors.

The exposure of isolated washed human neutrophils to purified human alpha1-antitrypsin resulted in a transient 2-fold enhancement of random migration and concomitant 70-90 per cent inhibition of chemotactic responsiveness to C5a or C3a, while treatment with alpha2-macroglobulin gave a less pronounced brief enhancement of random migration and prolonged 40-60 per cent suppression of chemotaxis. Peak effects occurred with concentrations of 1 mug/ml of alpha1-antitrypsin and 10 mug/ml of alpha2-macroglobulin. In contrast, the inhibitor of the activated first component of complement, at the highest concentration studied of 100/mug/ml, slightly enhanced chemotactic migration in response to C5a without influencing random migration. Preincubation of neutrophils with either L-1-tosylamide-2-phenylethyl-chloromethyl ketone (TPCK) or N-alpha-p-tosyl-L-lysine-chloromethyl ketone (TLCK) at concentrations of 10-8-10-4M suppressed chemotaxis with concomitant inhibition of random migration by TPCK and enhancement of random migration by TLCK. All agents worked directly and irreversibly on the cells but caused only slight stimulation of the activity of the hexose monophosphate shunt of layers of adherent neutrophils. The results suggest that interaction of the plasma alpha-globulins or synthetic esterase inhibitors with surface receptors on neutrophils can influence both the random migration and responsiveness to chemotactic factors of these cells.