Influence of pathological progression on the balance between cellular and humoral immune responses in bovine tuberculosis.

Studies of tuberculosis have suggested a shift in dominance from a T helper type 1 (Th1) towards a Th2 immune response that is associated with suppressed cell-mediated immune (CMI) responses and increased humoral responses as the disease progresses. In this study a natural host disease model was used to investigate the balance of the evolving immune response towards Mycobacterium bovis infection in cattle with respect to pathogenesis. Cytokine analysis of CD4 T-cell clones derived from M.

Identification of Mycobacterium bovis antigens by analysis of bovine T-cell responses after infection with a virulent strain.

Purification and characterization of individual antigenic proteins are essential for the understanding of the pathogenic mechanisms of mycobacteria and the immune response against them. In the present study, we used anion-exchange chromatography to fractionate cell extracts and culture supernatant proteins from Mycobacterium bovis to identify T-cell-stimulating antigens. These fractions were incubated with peripheral blood mononuclear cells (PBMC) from M.

Responses of bovine WC1(+) gammadelta T cells to protein and nonprotein antigens of Mycobacterium bovis.

WC1(+) gammadelta T cells of Mycobacterium bovis-infected cattle are highly responsive to M. bovis sonic extract (MBSE). In mycobacterial infections of other species, gammadelta T cells have been shown to respond to protein and nonprotein antigens, but the bovine WC1(+) gammadelta T-cell antigenic targets within MBSE require further definition in terms of the dominance of protein versus nonprotein components.

Immune responses in bovine tuberculosis.

Knowledge of the immune responses which develop in cattle following infection with Mycobacterium bovis is essential both to the understanding of disease pathogenesis and to the logical development of immune-dependent tools, such as diagnostic tests and vaccines, which can be used to combat the disease. Studies of field cases of bovine tuberculosis (TB) and of experimental bovine models of M. bovis infection have indicated that cell-mediated immune responses (CMI) predominate within a spectrum of immunity which exists.

Characterization of the early antibody response in bovine tuberculosis: MPB83 is an early target with diagnostic potential.

A 26-kDa antigen has been shown to be a dominant antibody target in Mycobacterium bovis-infected cattle. In this study, that antigen was used as an immunogen to raise a panel of mouse monoclonal antibodies. The majority of those bound to native protein with a molecular mass of 26 kDa and to recombinant MPB83, strongly suggesting that MPB83 is an important B-cell antigenic target in bovine tuberculosis.