title: B cell-deficient mice display markedly enhanced resistance to the intracellular bacterium Brucella abortus.
abstract: BACKGROUND
  Brucella species are facultative intracellular bacteria that cause lifelong infections in humans and livestock.
  
  
  METHODS
  Here we evaluated the contribution of B cells in control of murine brucellosis in the more susceptible BALB/c and the more resistant C57BL/6 mice by infecting B cell-deficient mice.
  
  
  RESULTS
  Strikingly, in the absence of B cells in both C57BL/6 and BALB/c mice, 99% and 99.5% of the infection found in wild type mice was cleared, respectively. This augmented clearance was not reversed in either strain by passive transfer of immune serum. In C57BL/6 mice, the clearance of infection coincided with an increase in interferon γ (IFN-γ)-producing CD4 and CD8 T cells and a reduction in interleukin 10 (IL-10)-producing cells. In BALB/c mice, this clearance was IFN-γ-dependent, as B cell/IFN-γ dual knockout mice were unable to clear the infection, and was inversely related to the levels of transforming growth factor β (TGF-β). Furthermore, B cells were found to produce TGF-β and IL-10 during early stages of infection in BALB/c wild-type and C57BL/6 wild-type mice, respectively.
  
  
  CONCLUSIONS
  Thus, we demonstrate that the establishment of the high plateau phase of infection is dependent on non-antibody-mediated B cell effector mechanisms, including B regulatory functions, during murine brucellosis.
authors: University of Massachusetts, Amherst, MA 01003, USA.
authors: Radhika
authors: R
authors: Goenka
authors: Michelle A
authors: MA
authors: Parent
authors: Philip H
authors: PH
authors: Elzer
authors: Cynthia L
authors: CL
authors: Baldwin
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial; D015703:Antigens, CD; D001402:B-Lymphocytes / Q000502:physiology*; D002003:Brucella abortus; D002006:Brucellosis / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes; D018414:CD8-Positive T-Lymphocytes; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D008212:Lymphocyte Depletion; D051379:Mice; D008815:Mice, Inbred Strains; D013154:Spleen / Q000166:cytology
chemical_list: D000907:Antibodies, Bacterial; D015703:Antigens, CD; D007371:Interferon-gamma