Modulation of human lymphocyte responses by neutrophil-derived factors: effects of neutrophils and neutrophil-derived factos.

Lymphocytes and polymorphonuclear neutrophils (PMNs) occur together in inflammatory sites. We have examined the possibility that PMNs, or PMN-derived factors, might influence human peripheral blood lymphocyte (PBL) functions. PBL were cultured with or without antigen or phytomitogen, and with or without purified PMNs, PMN lysates or supernatants (SPTs) from PMNs that had phagocytized zymosan-complement complexes. PMN-derived enhancing and inhibitory activities were identified. Studies indicated: (1) PMNs exhibited concentration-dependent enhancement or inhibition of PVL methyl-3H-thymidine uptake; (2) lysates of PMNs similarly inhibited PBLs at high concentrations, enhanced with dilution, and inhibited with further dilution; (3) SPTs from PMN that had phagocytized zymosan-complement also exhibited concentration-dependent enhancement and inhibition; (4) inhibition did not result from (a) mitogen binding or inactivation, (b) exhaustion of in vitro nutrients, (c) change of expected kinetics of responses, (d) alterations of cell numbers or viability; (5) enhancement and inhibition of PBL persisted after exposure to PMN SPT and washing before stimulation; and (6) PMN SPTs increased PBL ability to rosette with sheep erythrocytes. These observations identified two or more PMN-derived factors that may be important in modulating lymphocyte responses in acute and chronic inflammation.