title: Cytokine mRNA expressed in tuberculin skin test biopsies from BCG-vaccinated and Mycobacterium bovis inoculated cattle.
abstract: To obtain a better understanding of the delayed-type hypersensitivity reaction to Mycobacterium bovis, we measured the expression of cytokine mRNA from tuberculin skin test biopsies of cattle. Non-vaccinated and BCG-vaccinated cattle were inoculated intratracheally with a low dose of virulent M. bovis or sham-inoculated and 20 weeks later were skin tested with tuberculin. At necropsy 1-2 weeks later, tuberculous lesions were found in six of the nine non-vaccinated and three of the nine BCG-vaccinated animals. All of the lesioned and the majority of the non-lesioned M. bovis inoculated cattle showed a distinct skin swelling response to tuberculin, irrespective of vaccination. However, cattle with tuberculous lesions displayed larger skin swelling responses than non-lesioned cattle. Tuberculin-induced expression of IFN-gamma, IL2, IL4, IL10 and TNF-alpha mRNA occurred in the skin biopsies of all of the lesioned, M. bovis inoculated animals except for an absence of tuberculin-induced TNF-alpha mRNA expression in two animals. A lower proportion of the non-lesioned M. bovis inoculated cattle displayed tuberculin-induced expression of the five cytokine mRNA. There was no evidence of a unique pattern of cytokine expression which could be used to distinguish between diseased and protected animals. By 28 weeks after vaccination, the three BCG-vaccinated, sham-inoculated cattle displayed minimal skin swelling response to tuberculin, but tuberculin-induced expression of IFN-gamma, IL2, IL4, IL10 and TNF-alpha mRNA was observed in skin biopsies of all of these animals.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000818:Animals; D001500:BCG Vaccine / Q000276:immunology*; D001483:Base Sequence; D002417:Cattle; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D004198:Disease Susceptibility / Q000276:immunology; D005260:Female; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D009163:Mycobacterium bovis / Q000276:immunology*; D012333:RNA, Messenger / Q000096:biosynthesis; D014374:Tuberculin Test; D014380:Tuberculosis, Bovine / Q000175:diagnosis / Q000209:etiology / Q000473:pathology
chemical_list: D001500:BCG Vaccine; D016207:Cytokines; D012333:RNA, Messenger