Neutrophil cytotoxicity for desialylated autologous human red cells in the presence of peanut agglutinin

Abstract

Normal human peripheral blood neutrophils have been shown to function as effector cells, exhibiting cytotoxic activity against allogeneic or desialylated autologous red cells and tumor cells in the presence of the plant lectins concanavalin A (ConA) and phytohemagglutinin (PHA). The present study demonstrates that human neutrophils are selectively cytotoxic against desialylated autologous erythrocytes in the presence of the plant lectin peanut agglutinin (PNA), which closely resembles the circulating anti-T agglutinin with specificity for exposed terminal beta D-galactosyl residues. Nondesialylated erythrocytes were resistant to lysis. This PNA-dependent neutrophil cytotoxicity (PNA-NC) was dependent on dose, time, temperature, and ratio of effector to target cells in a 4-hr 51Cr release assay. Optimum cytotoxicity (50-80%) was obtained within 4 hr with 20 micrograms/ml PNA and an erythrocyte:neutrophil ratio of 1:1 at 24 degrees C. The PNA-NC was completely abolished in the presence of 0.25 M galactose, the specific sugar substrate for PNA.