POTENTIATION OF C56-INITIATED LYSIS BY LEUKOCYTE CATIONIC PROTEINS, MYELIN BASIC-PROTEINS AND LYSINE-RICH HISTONES

  • 1 January 1976
    • journal article
    • research article
    • Vol. 30  (4) , 467-473
Abstract
Synthetic polycations such as poly-L-lysine (PLL) were recently shown to enhance [guinea pig] C.hivin.5.hivin.6 [activated 5th and 6th complement components]-initiated lysis by neutralization of serum-derived inhibitors of the C.hivin.5.hivin.6.hivin.7 [human C7] complex, collectively designated C.hivin.5.hivin.6.hivin.7-INH. In the present report, the effect of several naturally occurring polycations on C.hivin.5.hivin.6-initiated lysis was examined. Lysosomal granule extracts from rabbit peritoneal exudate cells potentiated C.hivin.5.hivin.6-initiated lysis via counteraction of C.hivin.5.hivin.6.hivin.7-INH in the fluid phase; this was dependent upon the amount of C.hivin.5.hivin.6.hivin.7-INH present and independent of cell concentration. The basic proteins of guinea-pig, bovine and monkey myelin as well as lysine-rich histones also potentiated EC.hivin.5.hivin.6.hivin.7 [C.hivin.5.hivin.6.hivin.7 fixed to sheep erythrocytes] formation, but this effect seemed to occur predominantly at the cell surface. The presence of biologically derived cationic proteins at sites of C activation during inflammation might lead to enhanced tissue damage by favoring the formation of cell-C.hivin.5.hivin.6.hivin.7 intermediates by either or both of these mechanisms.