B1b lymphocyte-derived antibodies control Borrelia hermsii independent of Fcα/μ receptor and in the absence of host cell contact.

Abstract

The critical role of IgM in controlling pathogen burden has been demonstrated in a variety of infection models. In the murine model of Borrelia hermsii infection, IgM is necessary and sufficient for the rapid clearance of bacteremia. Convalescent, but not naïve, B1b cells generate a specific IgM response against B. hermsii, but the mechanism of IgM-mediated protection is unknown. Here, we show that neither Fcα/μR, a high-affinity receptor for IgM, nor IgM-dependent complement activation is required for controlling B. hermsii. Bacteria in diffusion chambers with a pore size impermeable to cells were killed when diffusion chambers were implanted into either convalescent or passively immunized mice. Furthermore, adoptively transferred convalescent B1b cells in Rag1(-/-) mice produced specific IgM that also cleared B. hermsii in diffusion chambers independent of complement. These results demonstrate that IgM-mediated clearance of B. hermsii does not require opsonophagocytosis and indicate that a mechanism for in vivo B1b cell-mediated protection is through the generation of bactericidal IgM.

• Authors: Matthew J Colombo, David Abraham, Akira Shibuya, Kishore R Alugupalli
• Journal: Immunologic research (Immunol Res) Vol. 51 Issue 2-3 Pg. 249-56 (Dec 2011) ISSN: 1559-0755 [Electronic] United States
• PMID: 22139824 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Review)

Chemical References

• Antibodies, Bacterial
• Complement C3
• Immunoglobulin M
• Receptors, Fc

Topics

• Adoptive Transfer
• Animals
• Antibodies, Bacterial (immunology)
• Antibody-Dependent Cell Cytotoxicity
• B-Lymphocyte Subsets (immunology)
• B-Lymphocytes (immunology, transplantation)
• Borrelia (immunology, pathogenicity)
• Borrelia Infections (genetics, immunology)
• Cells, Cultured
• Complement C3 (genetics, immunology)
• Host-Pathogen Interactions
• Humans
• Immunoglobulin M (immunology)
• Mice
• Phagocytosis
• Receptors, Fc (immunology)
• Serum Bactericidal Antibody Assay