Lectin-dependent neutrophil-mediated cytotoxicity. I. Characteristics

Isolated normal human peripheral neutrophils became cytotoxic to chicken red blood cells (CRBC) in the presence of phytohaemagglutinin (PHA) and concanavalin A (Con A), a phenomenon which we have termed lectin-dependent neutrophilmediated cytotoxicity (LDNMC). Substantial cytotoxicity could be demonstrated by 1 h of incubation at 37 degrees. Isolated human peripheral lymphocytes were not cytotoxic to CRBC in the presence of these lectins, even after 18 h of incubation. Both PHA and Con A exhibited dose responses over a wide concentration range and displayed progressive, time-dependent cytotoxicity. Cytotoxicity for both PHA and Con A was greater at 37 degrees than at 22 degrees, and was undetectable at 4 degrees. CRBC as target cells were much more readily lysed than either sheep or human erythrocytes. Erythrophagocytosis did not appear to play a role.