IRCMS International Research Center for Medical Sciences

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IRCMS Seminars

[Mar. 11] 77th IRCMS seminar

February 24 2022

We would like to inform you that the 77th IRCMS seminar has been scheduled as below. We would be pleased to see many of you participating in the seminar.

Date       : March 11, 2022 (Friday)

Time     : 16:00-17:00
               * On-site and Online only
               * To follow the extended quasi-state of emergency, it will be held online only.



Speaker : Izumi Ohigashi, PhD
      Associate Professor
      Division of Experimental Immunology, Institute of Advanced Medical Sciences,
      University of Tokushima

Tilte       : The mechanism regulating the formation of thymus function

     Functionally competent and self-tolerant T cell repertoire is shaped through positive and negative selection in the cortical and medullary microenvironments of the thymus. The thymoproteasome specifically expressed in the cortical thymic epithelial cells (cTECs) is essential for the optimal generation of CD8+ T cells. Although how the thymoproteasome governs the generation of CD8+ T cells is not fully understood, accumulating evidence suggests that the thymoproteasome optimizes CD8+ T cell production through the processing of positively selecting-self-peptides associated with MHC class I molecules expressed by cTECs.
     In the medullary microenvironment, autoreactive T cells are eliminated by undergoing negative selection or differentiate into regulatory T cells to establish self-tolerance. For that, positively selected T cells in the thymic cortex migrate into the thymic medulla. CCR7-mediated chemokine signaling is important for the migration of positively selected T cells from the cortex to the medulla. Among the CCR7 ligands, we have found that CCL21Ser produced by medullary thymic epithelial cells (mTECs) has a non-redundant role in the establishment of self-tolerance in T cells.
     In this seminar, I would like to talk about the recent advances in the mechanism of thymoproteasome-dependent generation of CD8+ T cells, as well as the functional significance of CCL21Ser in the thymus.

  1. Kozai M, et al. Journal of Experimental Medicine 2017.
  2. Ohigashi I, et al. Cell Reports 2019.
  3. Ohigashi I, et al. Journal of Experimental Medicine 2021.

Anyone in Kumamoto University who wants to join is welcome; however, please pre-register by the following URL to secure your seat or receive the Zoom meeting information.

Flyer (Click for a larger image):