The thymic stromal cell line MTSC4 induced thymocyte apoptosis in a non-MHC-restricted manner.
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.
He
Xue Ying
XY
Department of Immunology, Peking University Health Science Center,38 Xueyuan Road, Beijing 100083, China.
Li
Juan
J
Qian
Xiao Ping
XP
Fu
Wen Xian
WX
Li
Yan
Y
Wu
Li
L
Chen
Wei Feng
WF
D000818:Animals; D017209:Apoptosis / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002450:Cell Communication / Q000276:immunology; D002460:Cell Line; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000276:immunology; D053222:Fas Ligand Protein; D008285:Major Histocompatibility Complex / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000276:immunology; D051379:Mice; D010455:Peptides / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D017154:Stromal Cells / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology; D019014:fas Receptor / Q000276:immunology
D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D008562:Membrane Glycoproteins; D010455:Peptides; D011948:Receptors, Antigen, T-Cell; D019014:fas Receptor