論文種別	原著(症例報告除く)
言語種別	英語
査読の有無	査読あり
表題	Ccl21a, Rather Than Ccl21b, is Essential for Thymocyte Migration in Mouse.
掲載誌名	正式名：European journal of immunology 略　 称：Eur J Immunol ISSNコード：15214141/00142980
掲載区分	国外
巻・号・頁	55(12),pp.e70114
著者・共著者	Ohigashi I, Kyuma H, Otsu E, Hayashi S, Takemoto T, Takahama Y
発行年月	2025/12
概要	Self-tolerance in T cells is a vital self-defense strategy for mammals to specifically respond to invading pathogens. During T cell development in the thymus, thymocytes migrate from the cortex to the medulla to sequentially acquire non-self-reactivity and self-tolerance. This cortex-to-medulla migration is regulated by CCR7-mediated chemokine signaling. Previous studies have identified CCL21 but not CCL19 as a functional ligand for this CCR7-dependent migration. CCL21 in the mouse is encoded by multiple genes, including CCL21Ser-encoding Ccl21a and several CCL21Leu-encoding genes, including Ccl21b. The importance of Ccl21a in thymocyte migration has been demonstrated, whereas the role of CCL21Leu-encoding genes remains unclear. By producing mice specifically deficient in Ccl21b, we show that Ccl21b plays little to no role in the cortex-to-medulla migration of developing thymocytes. CCL21Leu-encoding gene transcripts remain detectable even in the absence of Ccl21b, suggesting that Ccl21b is not a major source of CCL21Leu. We further show that the copy number of CCL21Leu-encoding genes is smaller than the currently estimated copy number in a public database. These findings underscore the predominant role of Ccl21a over Ccl21b in the mouse thymus.
DOI	10.1002/eji.70114
PMID	41420491