title: Studies on the interactions of immunostimulated macrophages and Yersinia enterocolitica O:8.
abstract: Immunological and electron microscopy investigations of the phagocytic and killing activities of peritoneal macrophages from rats and mice against Yersinia enterocolitica serotype O:8 cells were performed. The effect of in vivo application of cytoplasmic membranes (CM) from the stable Escherichia coli WF+ L-form on macrophage activity was also studied. It was established that rat macrophages more actively phagocytosed the plasmidless pYV(-) Y. enterocolitica cells, compared to the plasmid-bearing pYV(+) Y. enterocolitica cells. The killing ability against both variants of the Y. enterocolitica strain was significantly enhanced in macrophages from CM-treated rats after 2 h, 4 h, and 24 h incubation. The CM treatment enhanced the phagocytic activity of the macrophages. The in vitro interaction of normal and immunostimulated rat macrophages with both pYV(+) and pYV(-) variants of Y. enterocolitica did not lead to any additional apoptotic and necrotic changes in macrophages compared to control macrophages, which were cultivated without Y. enterocolitica. Electron-microscopic investigation showed that mouse macrophages eliminated Y. enterocolitica pYV(+) cells in vivo after 24 h. No engulfed or digested bacterial cells were observed. Activation of cell surfaces and vacuolization of macrophage cytoplasm, both of CM-treated non-infected and infected mice, were observed. The experimental results showed that Y. enterocolitica pYV(+) cells could be eliminated by peritoneal macrophages.
authors.affiliation: Institute of Microbiology, Bulgarian Academy of Sciences, Sofia. eivanova@microbio.bas.bg
authors.forename: E
authors.initials: E
authors.lastname: Ivanova
authors.forename: I
authors.initials: I
authors.lastname: Yanchev
authors.forename: H
authors.initials: H
authors.lastname: Najdenski
authors.forename: R
authors.initials: R
authors.lastname: Toshkova
authors.forename: P
authors.initials: P
authors.lastname: Dimitrova
authors.forename: V
authors.initials: V
authors.lastname: Manov
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000276:immunology; D004926:Escherichia coli / Q000166:cytology / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology; D008262:Macrophage Activation; D017737:Macrophages, Peritoneal / Q000276:immunology* / Q000382:microbiology; D051379:Mice; D008813:Mice, Inbred ICR; D008854:Microscopy, Electron; D010587:Phagocytosis; D051381:Rats; D017208:Rats, Wistar; D015009:Yersinia Infections / Q000276:immunology* / Q000382:microbiology; D015008:Yersinia enterocolitica / Q000235:genetics / Q000276:immunology*
chemical_list: D008070:Lipopolysaccharides