Identification of novel Mycobacterium bovis antigens by disection of crude protein fractions

VIRGINIA MEIKLE; A. ALITO; ANDREA SABINA LLERA; A. GIOFFRE; A. PERALTA; B.M. BUDDLE; ANGEL CATALDI

CLINICAL AND VACCINE IMMUNOLOGY

AMER SOC MICROBIOLOGY

Año: 2009 vol. 16 p. 1352 - 1359

1556-6811

Culture filtrate and cell extracts from Mycobacterium bovis cultures contain molecules which could promoteprotective immunity to tuberculosis in animals. Different protein fractions of M. bovis cultures were obtainedby elution electrophoresis and were tested in experimentally infected cattle. The fractions that elicited gammainterferon (IFN-g) responses were resolved by two-dimensional gel electrophoresis, and individual proteinswere identified by matrix-assisted laser desorption ionization–time of flight mass spectrometry. The openreading frames were cloned, expressed as their recombinant forms, and retested with naturally and experimentallyinfected animals. Eleven protein fractions were highly reactive, from which the Rv1636, HspX,Rv0138, Rv2524, EsxI, and Rv3740 recombinant proteins were obtained. EsxI and HspX were the antigens mostrecognized by the IFN-g release assay. In summary, a proteomic approach allowed the identification of novelantigens useful for the diagnosis of bovine tuberculosis.