Vaccination with live Escherichia coli expressing Brucella abortus Cu/Zn superoxide-dismutase: II. Induction of specific CD8+ cytotoxic lymphocytes and sensitized CD4+ IFN-gamma-producing cell.

Previously we reported that immunization with Escherichia coli DH5alpha-expressing Brucella abortus Cu/Zn superoxide dismutase [E. coli (pBSSOD)] induces a protective immune response in BALB/c mice. Here we studied the type of immune defense that the recombinant E. coli induces in mice using as our experimental model Brucella superoxide dismutase Cu/Zn presented by J744.A1 to sensitized lymphocytes as the target of specific lysis or as cytokine inductors. The results indicate that E. coli carrying the Cu/Zn gene was able to induce specific cytotoxic T cells, mainly from CD8(+) subpopulation and IFN-gamma-producing cells belonging in their vast majority to the CD4(+) subpopulation.