Mycobacterium avium subspecies paratuberculosis infection of cattle does not diminish peripheral blood-derived macrophage mycobactericidal activity.
Ruminants infected with Mycobacterium avium subspecies paratuberculosis consistently develop a multibacillary form of disease that is centered on the ileum. Mechanisms responsible for failure of macrophage function during multibacillary disease are incompletely characterized. Our data suggest that mycobactericidal functions are present, and potentially enhanced, in monocyte-derived macrophages from M. avium subsp. paratuberculosis infected cattle. Addition of CD4(+) T cells from infected animals to autologous in vitro infected macrophages did not increase bacterial killing. In contrast, CD4(+) T cells from non-infected animals did increase bacterial killing in autologous macrophages. In macrophages from both infected and non-infected cattle, bacterial killing appeared to be independent of interferon-gamma (IFN-gamma) and nitric oxide production.
Hostetter
J
J
Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, 50011, USA. jesseh@iastate.edu
Zhang
W
W
Simutis
F
F
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology*; D018920:Coculture Techniques / Q000379:methods; D015169:Colony Count, Microbial / Q000379:methods; D007371:Interferon-gamma / Q000276:immunology; D008262:Macrophage Activation / Q000276:immunology; D008264:Macrophages / Q000276:immunology* / Q000382:microbiology; D016927:Mycobacterium avium subsp. paratuberculosis / Q000276:immunology*; D009569:Nitric Oxide / Q000378:metabolism; D010283:Paratuberculosis / Q000276:immunology*; D014376:Tuberculosis / Q000662:veterinary
D009569:Nitric Oxide; D007371:Interferon-gamma