Mouse thymic stromal cell line 4 (MTSC4) is one of the stromal cell lines established in our laboratory. While losing the characteristics of epithelial cells, they express some surface markers shared with thymic dendr...Mouse thymic stromal cell line 4 (MTSC4) is one of the stromal cell lines established in our laboratory. While losing the characteristics of epithelial cells, they express some surface markers shared with thymic dendritic cells (TDCs). To further study the biological functions of these cells, we compared the capability of MTSC4 with TDCs in the induction of thymocyte apoptosis, using thymic reaggregation culture system. Apoptosis of thymocytes induced by MTSC4 and TDCs was measured by Annexin V and PI staining and analyzed by flow cytometry. We found that MTSC4 selectively augmented the apoptosis of CD4^+8^+ (DP) thymocytes. This effect was Fas/FasL independent and could not be blocked by antibodies to MHC class Ⅰ and class Ⅱ molecules. In addition, MTSC4 enhanced the apoptosis of DP thymocytes from different strains of mice, which implies that MTSC4-induced thymocyte apoptosis is not mediated by the TCR recognition of self peptide/MHC molecules. In contrast to MTSC4, thymocyte apoptosis induced by TDCs was MHC-restricted. Thus, MHC-independent fashion of stromal-DP thymocyte interaction may be one of the ways to induce thymocyte apoptosis in thymus. Our study has also shown that the interaction of MTSC4 stromal cells and thymocytes is required for the induction of thymocyte apoptosis.展开更多
Thymus is the primary lymphoid organ involved in the development of thymocytes.Maturation related events of thymocytes within thymus,especially the widely discussed directional migration of thymocytes,is regulated by ...Thymus is the primary lymphoid organ involved in the development of thymocytes.Maturation related events of thymocytes within thymus,especially the widely discussed directional migration of thymocytes,is regulated by chemokines via chemokine receptors mediated signaling pathway.Multiple types of chemokines and chemokine receptors,as components of the network-interaction within thymic microenvironment,are involved in the thymopoiesis.It appears that these chemokines are functionally redundant and such phenomenon may be explained not only by the promiscuous,non-one-to-one matching between ligands-receptors within CXC or CC chemokine subfamily,but also by the various spatio-temporal expression patterns within different cell types and developmental stages.The redundancy and regulation of thymus expressed chemokines and chemokine receptors during thymocyte development are herein discussed.Cellular & Molecular Immunology. 2004;1(4):266-273.展开更多
基金This work was funded by grants from Major State Bascic Research Development Program of China(No.G1999053904)National Natural Science Foundation of China(No.30271200)Young Scentist Cooperation Research Fund(No.39928019).
文摘Mouse thymic stromal cell line 4 (MTSC4) is one of the stromal cell lines established in our laboratory. While losing the characteristics of epithelial cells, they express some surface markers shared with thymic dendritic cells (TDCs). To further study the biological functions of these cells, we compared the capability of MTSC4 with TDCs in the induction of thymocyte apoptosis, using thymic reaggregation culture system. Apoptosis of thymocytes induced by MTSC4 and TDCs was measured by Annexin V and PI staining and analyzed by flow cytometry. We found that MTSC4 selectively augmented the apoptosis of CD4^+8^+ (DP) thymocytes. This effect was Fas/FasL independent and could not be blocked by antibodies to MHC class Ⅰ and class Ⅱ molecules. In addition, MTSC4 enhanced the apoptosis of DP thymocytes from different strains of mice, which implies that MTSC4-induced thymocyte apoptosis is not mediated by the TCR recognition of self peptide/MHC molecules. In contrast to MTSC4, thymocyte apoptosis induced by TDCs was MHC-restricted. Thus, MHC-independent fashion of stromal-DP thymocyte interaction may be one of the ways to induce thymocyte apoptosis in thymus. Our study has also shown that the interaction of MTSC4 stromal cells and thymocytes is required for the induction of thymocyte apoptosis.
文摘Thymus is the primary lymphoid organ involved in the development of thymocytes.Maturation related events of thymocytes within thymus,especially the widely discussed directional migration of thymocytes,is regulated by chemokines via chemokine receptors mediated signaling pathway.Multiple types of chemokines and chemokine receptors,as components of the network-interaction within thymic microenvironment,are involved in the thymopoiesis.It appears that these chemokines are functionally redundant and such phenomenon may be explained not only by the promiscuous,non-one-to-one matching between ligands-receptors within CXC or CC chemokine subfamily,but also by the various spatio-temporal expression patterns within different cell types and developmental stages.The redundancy and regulation of thymus expressed chemokines and chemokine receptors during thymocyte development are herein discussed.Cellular & Molecular Immunology. 2004;1(4):266-273.
