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De novo expression of MECA‐79 glycoprotein‐determinant on developing B lymphocytes in gut‐associated lymphoid tissues
Author(s) -
Sinha Rajesh K.,
Yang Guibin,
Alexander Cornelius,
Mage Rose G.
Publication year - 2006
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1111/j.1365-2567.2006.02457.x
Subject(s) - biology , lymphatic system , high endothelial venules , peyer's patch , germinal center , lymph , mesenteric lymph nodes , appendix , lymph node , lymphocyte , b cell , microbiology and biotechnology , addressin , immunology , spleen , antibody , pathology , cell , medicine , biochemistry , paleontology , integrin
Summary Rabbit is one of several species that depend on development of B lymphocytes in gut‐associated lymphoid tissues for primary immunoglobulin‐repertoire diversification. The rabbit appendix is an important site of early B‐lymphocyte development. We previously reported that peripheral lymph node addressin detected by monoclonal antibody (mAb) MECA‐79 played a role in recruitment of immature blood‐borne B cells into neonatal rabbit appendix. Here, we report expression of an ∼127 000 MW O ‐linked sulphated proteoglycan on developing B cells in appendix and Peyer's patches recognized by the mAb MECA‐79. Binding of the mAb to B lymphocytes was sensitive to enzyme treatment with O ‐sialoglycoprotease and expression was partially inhibited by sodium chlorate, a metabolic inhibitor of sulphation. The proportions of MECA‐79 + B lymphocytes gradually increased from < 0·5% at 3 days to > 70% at 6 weeks in appendix and Peyer's patches. The proportions of MECA‐79 + B lymphocytes in spleen and peripheral blood were very low (0·5–2%). However, the MECA‐79 determinant was detected on B cells in splenic germinal centres after immunization. In situ labelling of appendix cells showed that the MECA‐79 determinant was expressed on fluorescein‐labelled B lymphocytes that migrated from appendix into mesenteric lymph nodes. B‐cell MECA‐79 may be involved in interactions with T cells and/or dendritic cells. Alternatively, because we found that lymphatic endothelium in the thymus‐dependent area of appendix, a site for lymphocyte exit, expressed P‐selectin (CD62P), interaction of the MECA‐79 determinant on B cells with CD62P may have a role in the exit of B lymphocytes from rabbit appendix.