Inactivation of the type IV secretion system reduces the Th1 polarization of the immune response to Brucella abortus infection.

ABSTRACT: The Brucella abortus type IV secretion system (T4SS), encoded by the virB operon, is essential for establishing persistent infection in the murine reticuloendothelial system. To gain insight into the in vivo interactions mediated by the T4SS, we compared host responses elicited by B. abortus with those of an isogenic mutant in the virB operon. Mice infected with the B. abortus virB mutant elicited smaller increases in serum levels of immunoglobulin G2a, gamma interferon (IFN-gamma), and interleukin-12p40 than did mice infected with wild-type B. abortus. Despite equal bacterial loads in the spleen, at 3 to 4 days postinfection, levels of IFN-gamma were higher in mice infected with wild-type B. abortus than in mice infected with the virB mutant, as shown by real-time PCR, intracellular cytok

SUBMITTER: Rolan HG 

PROVIDER: S-EPMC2446720 | biostudies-literature | 2008 Jul

REPOSITORIES: biostudies-literature