IDENTIFICATION OF THE MAJOR T-CELL ANTIGENS PRESENT IN THE BRUCELLA-MELITENSIS B115 PROTEIN PREPARATION, BRUCELLERGENE OCB

Brucellergene is a commercial allergen prepared from Brucella melitens is strain B115 and containing at least 20 cytoplasmic proteins, These proteins were separated by SDS-PAGE, The unstained gel was divided int o IS fractions and proteins were eluted from the gel fractions, The ca pacity of the separated proteins to elicit delayed-type hypersensitivi ty (DTH) in infected guinea-pigs or to induce the production of interf eron-gamma (IFN-gamma) by blood cells from infected cattle was evaluat ed, The biological activity of the corresponding protein fractions blo tted on to nitrocellulose was measured in a lymphocyte blastogenesis a ssay, Among the 18 fractions tested, two - spanning the mel. wt ranges 17-22 (fraction 8) and 35-42-kDa (fraction 17) - showed the maximum b iological activity in the three tests, These fractions contain two ant igens, the Brucella bacterioferritin (BFR) and P39 proteins, Both prot eins are good candidates for the detection of cellular immunity to Bru cella.