1212 Lysis of Antibody - Coated Cells by Platelets

In the course of our studies on the role of complement in an t i se rum-media ted damage to allografts and xenografts of skin, we have observed that, whereas serum from C5 deficient mice fails, as expected, to lyse sensitized sheep erythrocytes (SRBC),I whole blood from these animals causes measurable lysis even when di luted 1:100 in saline. This lytic activity occurs only if the cells have reacted with ant ibody, and only if platelets and early acting components of complement (C) are present. It appears to involve mechanisms not previously described in the l i terature and it may be useful in s tudying the functions of platelets as well as in del ineat ing the cytotoxic potent ia l of antibody. We describe here the condit ions under which the p h e n o m e n o n occurs and we present evidence for the essential involvement of ant ibody, complement , and platelets.