题目: Claudin expression in the thymus and its implication in T-cell development

报告人：Yoko Hamazaki, Ph.D., Associate Professor, Department of Immunology and Cell Biology, Graduate school of Medicine, Kyoto University

时间：3月21日下午15:00

地点：学院二楼会议室

摘要：Tight junctions (TJs) are specialized structures for the epithelial barrier functions and Claudin (Cld) molecules play a central role in the formation and functions of TJs. The authors found that a portion of medullary TECs (mTECs) express Cld3 and 4, although TECs do not form cellular sheets nor are they involved in barrier functions. They also discovered that Cld3,4⁺ mTECs were particular TECs that express a high level of the autoimmune regulator (Aire) gene, which plays a crucial role in central tolerance against various tissue specific antigens and is responsible for autoimmune polyendocrinopathy-candiasis-ectodermal dystrophy (APECED). Furthermore, They succeeded in identifying the origin of thymic medulla by analyzing expression pattern of Cld3,4 during the ontogeny.　Interestingly, a portion of developing T cells also expressed Clds, especially Cld4. The expression was gradually decreased with age, whereas it was up-regulated in several autoimmune mouse models. Possible functions and immunological significance of Clds in thymic organogenesis and T cell development will be discussed.

代表论文:

1.          Hamazaki Y, Fujita H, Kobayashi T, Choi Y, Scott HS, Matsumoto M, Minato N.
Medullary thymic epithelial cells expressing Aire represent a unique lineage derived from cells expressing claudin.
Nat. Immunol. 2007 Mar; 8(3):304-311.

2.          Kawai Y, Hamazaki Y, Fujita H, Fujita A, Sato T, Furuse M, Fujimoto T, Jetten AM, Agata Y, Minato N.
Proc Natl Acad Sci U S A. 2011 Feb 15. [Epub ahead of print] Claudin-4 induction by E-protein activity in later stages of CD4/8 double-positive thymocytes to increase positive selection efficiency.