Depletion of immature B cells during Trypanosoma cruzi infection: involvement of myeloid cells and the cyclooxygenase pathway.
The ability of a microorganism to elicit or evade B cell responses represents a determinant factor for the final outcome of an infection. Although pathogens may subvert humoral responses at different stages of B cell development, most studies addressing the impact of an infection on the B cell compartment have focused on mature B cells within peripheral lymphoid organs. Herein, we report that a protozoan infection, i.e. a Trypanosoma cruzi infection, induces a marked loss of immature B cells in the BM, which also compromises recently emigrated B cells in the periphery. The depletion of BM immature B cells is associated with an increased rate of apoptosis mediated by a parasite-indirect mechanism in a Fas/FasL-independent fashion. Finally, we demonstrated that myeloid cells play an important role in B cell depletion, since CD11b(+) BM cells from infected mice secrete a product of the cyclooxygenase pathway that eliminates immature B cells. These results highlight a previously unrecognized maneuver used by a protozoan parasite to disable B cell generation, limiting host defense and favoring its chronic establishment.
Zuniga
Elina
E
Department of Clinical Biochemistry, School of Chemical Science, National University of Cordoba, Argentina.
Acosta-Rodriguez
Eva
E
Merino
Maria Cecilia
MC
Montes
Carolina
C
Gruppi
Adriana
A
D000818:Animals; D017209:Apoptosis; D001402:B-Lymphocytes / Q000276:immunology*; D014355:Chagas Disease / Q000276:immunology*; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D022423:Myeloid Cells / Q000502:physiology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000502:physiology*; D011453:Prostaglandins / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology; D019014:fas Receptor / Q000502:physiology
D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D008562:Membrane Glycoproteins; D011453:Prostaglandins; D014409:Tumor Necrosis Factor-alpha; D019014:fas Receptor; D011451:Prostaglandin-Endoperoxide Synthases