Molecular biology of Chlamydia pneumoniae surface proteins and their role in immunopathogenicity

• Published in: The American heart journal Vol. 138; no. 5; pp. S491 - S495
• Main Authors: Christiansen, Gunna, Boesen, Thomas, Hjernø, Karin, Daugaard, Lene, Mygind, Per, Madsen, Anna Sofie, Knudsen, Katrine, Falk, Erling, Birkelund, Svend
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY Mosby, Inc 01.11.1999; Elsevier
• Subjects: Animals; Antibodies, Monoclonal - metabolism; Atherosclerosis (general aspects, experimental research); Bacterial Outer Membrane Proteins - genetics; Bacterial Outer Membrane Proteins - immunology; Bacterial Outer Membrane Proteins - metabolism; Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Chlamydophila pneumoniae - metabolism; Chlamydophila pneumoniae - pathogenicity; Electrophoresis, Polyacrylamide Gel; HeLa Cells; Humans; Immunoblotting; Immunohistochemistry; Lipopolysaccharides - metabolism; Lung - metabolism; Lung - microbiology; Lung - pathology; Medical sciences; Mice; Mice, Inbred C57BL; Microscopy, Immunoelectron; Molecular Weight; Protein Conformation; Serologic Tests; Virulence; Immunohistochemistry; Immunopathology; Chlamydia pneumoniae; Chlamydiaceae; Pathogenesis; Rodentia; Cardiovascular disease; Infection; Vascular disease; Pathology; Vertebrata; Mammalia; Mouse; Animal; Atherosclerosis; Chlamydiales; Bacteria; Molecular biology
• ISSN: 0002-8703; 1097-6744
• DOI: 10.1016/S0002-8703(99)70283-8

Background The association of Chlamydia pneumoniae with the development of atherosclerosis is based on serology and on detection of C pneumoniae –specific DNA by polymerase chain reaction in the atheromas. Methods and Results Because the humoral immune response frequently recognizes epitopes present on the surface of the bacteria, we analyzed what components are present on the C pneumoniae surface. We identified a family of proteins, the GGAI or Omp4-15 proteins, of which at least 3 are present on the surface of C pneumoniae . We immunized rabbits with recombinant GGAI proteins and used these antibodies in immunofluorescence microscopy of experimentally infected mice. In lung sections, a massive infiltration with polymorph nuclear neutrophil cells was observed. In the bronchial epithelial cells, C pneumoniae inclusions were seen. Evidence was found of differential expression of the GGAI proteins. Conclusions On the basis of surface localization, differential expression, and the fact that the proteins are recognized by the human humoral immune response, we speculate whether these proteins, in addition to the lipopolysaccharides, are of importance for the immunopathogenesis of C pneumoniae . (Am Heart J 1999;138:S491-S495.)