title: Demonstration of bacterial antigen in macrophages in experimental pyelonephritis.
abstract: The immunomorphological characteristics of interstitial macrophages with PAS-positive granules were studied in experimental Escherichia coli pyelonephritis in rats, using an anti-E. coli antibody. Immunohistochemical, immunoelectron microscopical, as well as light- and electron microscopical findings were compared at twelve time points between 2 days and 13 weeks after infection. Macrophages with PAS-positive granules were present in the inflammatory infiltrates from the 7th day. The granules were phagolysosomes, filled predominantly with myelin figures. The myelin figures originated mainly from the constituents of the bacterial wall and reacted with the anti-E. coli antibody even 13 weeks after infection. The storage of bacterial residues with preserved antigenic structures for several weeks after infection indicates disturbed phagolysosomal elimination of the bacterial substances in the PAS-positive macrophages. In the formation of macrophages with PAS-positive granules, lysosomal overloading with large amounts of bacteria and cell debris is assumed, leading to consumption of the lysosomal enzymes, consequent incomplete breakdown and retention of the bacterial residues.
authors.affiliation: Department of Pathology, Albert Szent-Györgyi Medical University, Szeged, Hungary.
authors.forename: B
authors.initials: B
authors.lastname: Iványi
authors.forename: T
authors.initials: T
authors.lastname: Krenács
authors.forename: E
authors.initials: E
authors.lastname: Dobó
authors.forename: J
authors.initials: J
authors.lastname: Ormos
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis*; D003594:Cytoplasmic Granules / Q000473:pathology; D004926:Escherichia coli / Q000276:immunology / Q000302:isolation & purification*; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D007684:Kidney Tubules / Q000473:pathology; D008214:Lymphocytes / Q000473:pathology; D008247:Lysosomes / Q000473:pathology; D008264:Macrophages / Q000382:microbiology* / Q000473:pathology; D008297:Male; D016253:Microscopy, Immunoelectron; D009336:Necrosis; D009504:Neutrophils / Q000473:pathology; D010503:Periodic Acid-Schiff Reaction; D011704:Pyelonephritis / Q000382:microbiology* / Q000473:pathology; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000942:Antigens, Bacterial