Cutting edge: organogenesis of nasal-associated lymphoid tissue (NALT) occurs independently of lymphotoxin-� (LT �) and retinoic acid receptor-related orphan receptor-�, but the organization of NALT is LT � dependent

Abstract

Peyer’s patch and nasal-associated lymphoid tissue (NALT) are mucosal lymphoid tissues that appear similar in structure and function. Surprisingly, we found that NALT, unlike Pey-er’s patch, was formed independently of lymphotoxin (LT). Furthermore, using mice deficient in the retinoic acid receptor-related orphan receptor-, we found that NALT was formed in the absence of CD4CD3 cells, which are thought to be the embryonic source of LT. However, we also found that NALT of LT/ animals was disorganized and lymphopenic, sug-gesting that the organization and recruitment of lymphocytes within NALT remained dependent on LT. Finally, we dem-onstrated that both the structure and function of NALT were restored in LT/ animals upon reconstitution with normal bone marrow. These results demonstrate that the organogen-esis of NALT occurs through unique mechanisms. The Jour