Characterization and possible mechanisms of mitogen-induced cell-mediated cytotoxicity

Mitogen-induced cell-mediated cytotoxicity (MICC) of human peripheral blood granulocytes (PMN) and lymphocytes (PBL) was studied by using chicken erythrocytes as targets. The possible mechanisms were elicited bidirectionally by means of the MICC inhibition test and by functional analysis of lectin. In our preliminary data it was noted that PMN-mediated cytotoxicity was more potent than that of PBL. In addition, erythrophagocytosis or lysosomal enzymes released from PMN offered little contribution to cytotoxic activity of PMN. From the inhibition study it was realized that intact cytoskeletal structures, functionally preserved membrane lectin receptors, active DNA synthesis, and environmental divalent cations were mandatory for the full expression of MICC activity by both effectors. We also identified the cytotoxic activity of PHA-P as having a unique character that is thermostable and independent of the other biological activities.