Brucella abortus subverts B-cell function through macrophages as a virulence strategy

JUAN M. SPERA, CLAUDIA K. HERRMANN, MARA S. ROSET, DIEGO J. COMERCI AND JUAN E. UGALDE

Chicago

Conferencia; 65th Brucellosis Research Conference; 2012

B-lymphocytes and opsonizing antibodies are two central functions of the immune system necessary to control infections. We report here that Brucella abortus subverts these functions as a virulence strategy. We show that, in vivo, B. abortus virulence factor prpA is responsible for an increment in the B-cell number and the specific antibody response and that these antibodies promote cell infection. Although PrpA affects B-cell number and function, it targets macrophages, where it is translocated during infection. We observed that PrpA treated macrophages induce the secretion of a soluble factor responsible for B-cell proliferation and identified Myh9 as a receptor required for binding and function of this virulence factor in vitro and in vivo.