Wirkung von Antikörpern und Komplement auf die Interaktion zwischen Escherichia coli 0111:B4 und Granulozyten

Abstract

The interaction of Escherichia coli 0111:B4 with polymorphonuclear leukocytes in the presence of specific antibodies and complement was studied. This strain, which is resistant to phagocytosis by polymorphonuclear leukocytes, may be ingested and killed by the phagocytes in the presence of both antibodies and fresh serum. The ineffectiveness of fresh serum to promote ingestion of E. coli 0111:B4 by the phagocytes in the absence of antibodies reflects the inability of this strain to activate the complement system through the alternative pathway. Investigation of the mechanisms of the bacterial killing by polymorphonuclear leukocytes showed that both antibodies and complement were required for the oxygen-independent bactericidal system, whereas they were not needed for the oxygen-dependent system.

Kinetics of assembly and decay of complement components on Escherichia coli O111:B4 preparation of stable intermediates

“…Partially purified human C3 and C5 were purchased from Cordis Laboratories, Miami, Fla. Highly purified C8 and C9 were isolated as described by Steckel KSCN and hydrazine hydrate, following the procedure described for guinea pig serum by Dalmasso and Muller-Eberhard (4). Natural antibodies against E. coli 0111:B4 were removed from human serum by absorption as previously described (15).…”

“…In .previous studies we provided evidence for the contribution of surface-bound complement components to the intracellular killing of Escherichia coli O111:B4 by human polymorphonuclear leukocytes (PMN) (15,21). This novel effect of the human complement system was found to depend on the components of the complement sequence assembled on the surface of the bacteria, since bound C5 and C8 promoted killing, whereas C3 and C7 were ineffective in this regard (21; G. D. Rottini, F. Tedesco, L. Roncelli, and P. Patriarca, Eur.…”

Bactericidal-activities of human polymorphonuclear leukocyte proteins against Escherichia coli O111:B4 coated with C5 or C8

“…Evidence has also been provided in favor of an additional role of complement in potentiating the bactericidal activity of the phagocytes once the bacteria have been engulfed (6,8,10). Thus, components of the alternative pathway promote the intracellular killing of Staphylococcus by the monocytes (7) and the late-acting components promote that of Escherichia coli 0111:B4 by the polymorphonuclear leukocytes (PMN) (15). More detailed investigations performed by our group on the components involved in the processing of E. coli 0111:B4 by PMN revealed an absolute requirement of membrane-bound C5 or C8 for effective killing of the bacteria (21).…”