Age dependent lytic activities of the rat erythrocytes by anti-phosphatidycholine monoclonal antibody

Abstract

A series of anti-phosphatidylcholine monoclonal antibodies (anti-PC mAbs) were established and characterized. Among them, JE-1 not only showed strong lytic activity against the phosphatidylcholine (PC) membrane measured by the complement dependent liposome lysis assay, but could also hemolyze intact mouse and human erythrocytes in a complement dependent manner. Furthermore, it showed different lytic activity against fractionated rat erythrocytes. The bottom fraction (older erythrocyte) showed more remarkable increasing lytic activity than the top fraction (younger erythrocyte). On the one hand, the bottom sialic acid contents decreased by 30.7% compared with those of the upper. [i25I]JE-l binding activity to rat erythrocytes strongly suggested that there were some changes on the membrane PC conformation with age. Treatment of the -SH oxidizing agent (diamide) facilitated the PC transfer from outer monolayer to inner monolayer of the membrane. These results suggested that age dependent membrane lytic activity by JE-1 might be generated because of the perturbation of PC conformation or erythrocyte membrane.