title: Distinct response kinetics of gamma interferon and interleukin-4 in bovine tuberculosis.
abstract: This study shows that gamma interferon (IFN-gamma) and interleukin-4 (IL-4) cytokine responses are produced by peripheral blood cells in cattle infected with Mycobacterium bovis. The different kinetics of the IFN-gamma and IL-4 responses to bovine tuberculin and to ESAT-6 following experimental intratracheal infection with M. bovis are described. An early increase in IFN-gamma was observed that was maintained throughout the period studied. In contrast, the IL-4 response was delayed and confined to a peak of activity lasting 6 to 8 weeks. Interestingly, an experimental challenge of cattle with a lower dose of M. bovis which did not result in the development of lesions, positive DTH skin test, or substantial IFN-gamma responses nevertheless generated strong specific IL-4 responses. Investigation of naturally infected M. bovis field reactors showed increased IFN-gamma and IL-4 responses compared to uninfected cattle and that both of these cytokines were equally able to differentiate infected from uninfected animals. The magnitude of the M. bovis-induced IL-4 responses were found to be similar to the antigen-specific IL-4 responses of cattle infected with the parasitic nematode Onchocerca ochengi, further supporting the presence of this type 2 cytokine in bovine tuberculosis.
authors.affiliation: TB Research Group, Veterinary Laboratories Agency, Addlestone, Surrey KT15 3NB, United Kingdom. srhodes.vla@gtnet.gov.uk
authors.forename: S G
authors.initials: SG
authors.lastname: Rhodes
authors.forename: N
authors.initials: N
authors.lastname: Palmer
authors.forename: S P
authors.initials: SP
authors.lastname: Graham
authors.forename: A E
authors.initials: AE
authors.lastname: Bianco
authors.forename: R G
authors.initials: RG
authors.lastname: Hewinson
authors.forename: H M
authors.initials: HM
authors.lastname: Vordermeier
mesh_terms: D000818:Animals; D002417:Cattle; D005260:Female; D007371:Interferon-gamma / Q000096:biosynthesis*; D015847:Interleukin-4 / Q000096:biosynthesis*; D009855:Onchocerciasis / Q000276:immunology; D014380:Tuberculosis, Bovine / Q000276:immunology* / Q000473:pathology
chemical_list: D015847:Interleukin-4; D007371:Interferon-gamma