Two Distinctive Pathways for Recruitment of Naïve and Primed IgM+B Cells to the Gut Lamina Propria

• Published in: Proceedings of the National Academy of Sciences - PNAS 2005-02, Vol.102 (7), p.2482-2486
• Main Authors: Suzuki, Keiichiro, Meek, Bob, Doi, Yasuko, Honjo, Tasuku, Fagarasan, Sidonia
• Format: Article
• Language: English
• Subjects: Animals; B lymphocytes; B-Lymphocytes - immunology; B-Lymphocytes - physiology; Base Sequence; Biological Sciences; Bone Marrow Cells - immunology; Bone Marrow Cells - physiology; Cell adhesion & migration; Cell Movement; Digestive system; Digestive System - cytology; Digestive System - immunology; DNA - genetics; Enzymes; Immunoglobulin M - metabolism; Immunology; Integrins; Intestines; Lymphocytes; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Mutant Strains; Mice, Transgenic; Parabiosis; Peyer's Patches - cytology; Peyer's Patches - immunology; Plasma cells; Reverse Transcriptase Polymerase Chain Reaction; Small intestine; Spleen; Stromal cells
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0409539102

Intestinal IgA+B cells are generated from IgM+B cells by in situ class switching in two separate gut microenvironments: organized follicular structures and lamina propria (LP). However, the origin of IgM+B cells in the gut LP is unknown. Transfer experiments to reconstitute IgM+B cells and IgA plasma cells in LP of aly/aly mice, which are defective in all organized follicular structures because of an NF-κB-inducing kinase (NIK) mutation, revealed that naïve B cells can directly migrate to the LP. This migration requires NIK-dependent activation of gut stromal cells. By contrast, the entry of gut-primed IgM+B cells to the LP is independent of stromal cells with functional NIK. Our results indicate that naïve B cells directly migrate to the LP by a distinct pathway from gut-primed B cells.