Influence of Mycobacterium tuberculosis catalase gene (KatG) expression on nitric oxide production and the intracellular growth of transfected Mycobacterium smegmatis strains within murine macrophages.
Expression or possession of catalase gene may interfere with the iNOS/NO pathway in mycobacteria, hence altering their capacity to survive within macrophages. Therefore, strains of M. smegmatis with an inactive catalase-peroxidase gene (KatG), or into which the KatG gene of Mycobacterium tuberculosis had been transfected, were used to study the influence of catalase on nitric oxide (NO) production and mycobacterial survival within infected murine 1774 macrophages. High levels of nitrite (40-70 nM) were detected in IFN-gamma and LPS activated, infected murine cell culture supernatants, however, NO2- titres produced by infected murine cells did not differ between various catalase phenotype strains. Similarly, no significant difference in mycobacterial killing was also observed among the five strains of M. smegmatis tested over a 3 day infection period.
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Department of Immunology, University of Birmingham, UK.
D000818:Animals; D002374:Catalase / Q000235:genetics* / Q000494:pharmacology; D002460:Cell Line; D015870:Gene Expression; D007371:Interferon-gamma / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000382:microbiology*; D051379:Mice; D009161:Mycobacterium / Q000254:growth & development*; D009169:Mycobacterium tuberculosis / Q000201:enzymology* / Q000235:genetics; D009569:Nitric Oxide / Q000096:biosynthesis*; D014162:Transfection
D008070:Lipopolysaccharides; D009569:Nitric Oxide; D007371:Interferon-gamma; D002374:Catalase