Studies on Immune Cellular Injury

Abstract

It was demonstrated in the preceding paper (1) that incubation of primary isolates of normal human amnion cells with specific rabbit antibody and normal human serum resulted in immune cellular injury as measured by two independent criteria of cytotoxicity. It was further shown that the factors in normal human serum which were required in addition to specific antibody for production of cytotoxicity were indistinguishable from components of hemolytic complement and calcium and magnesium ions. Thus, no fundamental differences were apparent between requirements for immune injury of human amnion cells (immune cytotoxicity) and immune injury of sheep or human erythrocytes (immune hemolysis) (2, 3).The sequence of action of the components of complement in immune hemolysis was deduced by Pillemer, Seifter, and Ecker (4). In further dissection of this complex system, Mayer, Levine, and their associates showed that early events in immune hemolysis involved reactions between the sensitized erythrocyte and the first and fourth components of complement (C'I and C~4) in the presence of Ca ++ . The resulting complex could then react with the second component of complement (C'2) in the presence of Mg ++, forming a complex which could react with the third component (CI3) in the absence of divalent cations. The latter reaction effected injury of the erythrocyte leading to hemolysis (2). The biochemical as opposed to the descriptive events in immune hemolysis were unknown.A large body of evidence has accumulated from this laboratory and independently from Becker's laboratory that C'I is a proenzyme which may be activated by antigen-antibody reactions (5). The active enzyme is an esterase (C'I esterase) capable of hydrolyzing certain synthetic amino acid esters, such as N-acetyl-L-tyrosine ethyl ester and p-toluenesulfonyl-L-arginine methyl *

Studies on Immune Human Hemolysis

“…from its naturally occurring proenzyme to the active enzyme, C~I esterase (5). They are str~Mngly similar to current observations on the role of complement in immune cytotoxlcity, studies in which the deleterious effects of complement on human amnion cells in the presence of specific antibody were initiated by C'I esterase (17,21). They are also similar to the data previously reported on the sequence of events in complement fixation by antigen-antibody aggregates (5).…”

“…The observations on the effect of inhibitor in the D-L reaction were therefore similar to other studies on the role of inhibitor in complement fixation (22) and immune cytotoxicity (21).…”

The Thyroid Cytotoxic Autoantibody

“…In view of the lack of penetration of antibodies into living cells, the ability of trypsinized cell suspensions to absorb out cytotoxic activity from Hashimoto serum also argues for combination occurring at the cell surface. Previous studies on immune cytolysis with other cell systems such as HeLa cells (18,19), and immune hemolysis (20), have emphasized the importance of cell surface interactions with the antibody. Electron microscope studies using ferritin-labeled antibody to HeLa cells (21), have shown that antibody combination is restricted to the cell surface until after the addition of complement, when binding to the subcellular elements of the cytoplasm can be observed after rupture of the cell membrane.…”

Effects of Specific Antibodies on Tissue Cells

“…More recently, Ross & Lepow (25,26) have studied this same general mechanism of cell injury further and have implicated the C1 esterases in the cytotoxic reaction. They have also established the importance of calcium and magnesium in this immune reaction, and they have worked out the critical sequence in which the multiple reactions, involving each of the components of complement, must take place.…”