Phagocytosis of enteropathogenic Escherichia coli and Candida albicans by lectin-like receptors.
1. Ingestion of enteropathogenic Escherichia coli or Candida albicans by thioglycollate-elicited macrophages and polymorphonuclear leukocytes was investigated in vitro, 2. Goat antiserum against mannose receptors caused about 50% inhibition of E. coli phagocytosis and about 90% inhibition of C. albicans phagocytosis. 3. E. coli and C. albicans uptake was inhibited by about 60% and 98%, respectively, by plating the macrophages onto substrates coated with poly-L-lysine-mannan. Further addition of 50 mM mannose to the medium significantly increased the inhibition of phagocytosis of E. coli by macrophages from 60.7 +/- 1.5 to 79.8 +/- 13.1 and by polymorphonuclear cells from 58.9 +/- 3.7 to 88.7 +/- 4.9. 4. Preincubation of phagocytic cells with antiserum against substance A of human erythrocytes reduced E. coli ingestion by 95%, but this inhibition was not observed when the antiserum was incubated with N-acetylgalactosamine (50 mM) before being added to the phagocytes. The phagocytosis of C. albicans was not inhibited by anti-substance A antiserum. 5. The phagocytosis of E. coli was inhibited by about 25% by the addition of 7.8 micrograms/ml soluble mannan to the medium, and by about 50% by the addition of 50 mMN-acetylgalactosamine; when both substances were added to the medium, an additive inhibition of about 75% was observed. 6. These results indicate that mannose receptors on the surface of phagocytic cells mediate E. coli or Candida albicans uptake and that the binding of bacteria to N-acetylgalactosamine residues from the membrane of phagocytes is also involved in the phagocytosis of E. coli.
Pacheco-Soares
C
C
Departamento de Patologia Geral, Universidade Estadual de Londrina, PR, Brasil.
Gaziri
L C
LC
Loyola
W
W
Felipe
I
I
D000116:Acetylgalactosamine / Q000494:pharmacology; D000818:Animals; D001422:Bacterial Adhesion / Q000187:drug effects / Q000276:immunology; D002176:Candida albicans / Q000187:drug effects / Q000276:immunology* / Q000472:pathogenicity; D003864:Depression, Chemical; D004912:Erythrocytes / Q000187:drug effects / Q000276:immunology; D004926:Escherichia coli / Q000187:drug effects / Q000276:immunology* / Q000472:pathogenicity; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology; D037181:Lectins, C-Type; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000276:immunology; D008351:Mannans / Q000494:pharmacology; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D051379:Mice; D010587:Phagocytosis / Q000187:drug effects / Q000276:immunology*; D011956:Receptors, Cell Surface / Q000276:immunology; D011975:Receptors, Mitogen / Q000187:drug effects / Q000276:immunology*
D007106:Immune Sera; D037181:Lectins, C-Type; D008351:Mannans; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D011956:Receptors, Cell Surface; D011975:Receptors, Mitogen; D000116:Acetylgalactosamine