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Microbial Induction of T Cell Areas in the Rabbit Appendix
Author(s) -
Lanning Dennis Keith,
Hanson Nicholas Buck
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.843.12
Subject(s) - appendix , biology , cell , chemokine , cell growth , immunology , microbiology and biotechnology , genetics , inflammation , paleontology
The rabbit appendix contains multiple B cell follicles separated at their sub‐apical regions by well‐defined T cell areas. We found, by RNA in situ hybridization, that the T cell chemoattractant SLC (secondary lymphoid tissue chemokine, or CCL21) is highly expressed in the T cell areas of adult rabbit appendix. We unexpectedly also found, however, that the localized expression of SLC differs dramatically in early neonatal appendix. SLC was first expressed about two days after birth in a continuous layer beneath the B cell clusters. As B cells accumulated and began proliferating over subsequent days, developing follicles grew down through the layer of SLC expression, ultimately generating the characteristic organization of B and T cell areas seen in adult appendix. Furthermore, by introducing bacterial isolates into appendices rendered germfree through ligation at birth, we found that T cell area development is dependent on intestinal commensals, and that individual commensals differed in their ability to induce T cell areas. Microbial induction of T cell areas in the rabbit appendix might be important for supporting B cell proliferation and V(D)J gene diversification in appendix follicles, which generate the primary antibody repertoire. This work was supported by NIH grant 1 RO1 AI49458‐01A1.