1. Chemokine-mediated B cell trafficking during early rabbit GALT development.
- Author
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Zhai SK, Volgina VV, Sethupathi P, Knight KL, and Lanning DK
- Subjects
- Animals, Animals, Newborn, Appendix immunology, Appendix metabolism, Chemokine CCL19 genetics, Chemokine CCL19 metabolism, Chemokine CCL20 genetics, Chemokine CCL20 metabolism, Chemokine CCL21 genetics, Chemokine CCL21 metabolism, Chemokine CXCL12 genetics, Chemokine CXCL12 metabolism, Chemokine CXCL13 genetics, Chemokine CXCL13 metabolism, Cytidine Deaminase genetics, Cytidine Deaminase metabolism, Gene Expression, Immunohistochemistry, Immunophenotyping, Models, Biological, Phenotype, RNA, Messenger genetics, Rabbits, Receptors, CXCR4 genetics, Receptors, CXCR4 metabolism, Receptors, Chemokine genetics, Receptors, Chemokine metabolism, AICDA (Activation-Induced Cytidine Deaminase), B-Lymphocytes immunology, B-Lymphocytes metabolism, Cell Movement, Chemokines metabolism
- Abstract
Microbial and host cell interactions stimulate rabbit B cells to diversify the primary Ab repertoire in GALT. B cells at the base of appendix follicles begin proliferating and diversifying their V-(D)-J genes around 1 wk of age, ∼5 d after B cells first begin entering appendix follicles. To gain insight into the microbial and host cell interactions that stimulate B cells to diversify the primary Ab repertoire, we analyzed B cell trafficking within follicles during the first week of life. We visualized B cells, as well as chemokines that mediate B cell homing in lymphoid tissues, by in situ hybridization, and we examined B cell chemokine receptor expression by flow cytometry. We found that B cells were activated and began downregulating their BCRs well before a detectable B cell proliferative region appeared at the follicle base. The proliferative region was similar to germinal center dark zones, in that it exhibited elevated CXCL12 mRNA expression, and B cells that upregulated CXCR4 mRNA in response to signals acquired from selected intestinal commensals localized in this region. Our results suggest that after entering appendix follicles, B cells home sequentially to the follicle-associated epithelium, the follicular dendritic cell network, the B cell/T cell boundary, and, ultimately, the base of the follicle, where they enter a proliferative program and diversify the primary Ab repertoire., (Copyright © 2014 by The American Association of Immunologists, Inc.) more...
- Published
- 2014
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