Characterization of a 50 kDa surface membrane protein on thymic stromal cells as an important factor for early T cell development.
We previously reported that the nude mouse-derived splenic T cell clone, N-9F, exhibits a proliferative response to the SL10.3 thymic epithelial cell clone. In the present study we generated an Armenian hamster mAb, HS9, specific for SL10.3, which inhibited the N-9F's proliferative response to SL10.3. We performed thymocyte repopulation experiments using fetal liver cells and 2'-deoxyguanosine-treated thymic rudiments. After 14 days of culture, donor fetal liver cells proliferated and differentiated to CD4+CD8+ and CD4-CD8+ with some CD4+CD8- cells in the host thymic rudiments. However, most of the thymocytes remained at a CD4-CD8- immature stage in the presence of HS9 and the cell recovery was reduced to 30% of the control. Immunohistostaining and flow cytometry studies revealed that HS9 reacted with stromal cells of fetal thymus at the earliest from day 14 gestation. Neither thymocytes nor lymph node T cells were stained with HS9. HS9 antigen was distributed not only on thymic subcapsular and cortical stromal cells, but also on peripheral B cells in adult mice. The antigen that HS9 detected was found to be a 50 kDa surface membrane protein on thymic stromal cells. On the other hand, the 50 kDa molecule is associated with two other molecules of 80 and 100 kDa on the B cells. These data indicate that the HS9 antigen may have an important role for early T cell development, especially at a stage from CD4-CD8- to CD4+CD8+, and may have some unknown function on B cells.
Takeuchi
T
T
Department of Immunology, National Institute of Neuroscience, Tokyo, Japan.
Tamamoto
T
T
Tamura
H
H
Yamamoto
H
H
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000494:pharmacology; D001402:B-Lymphocytes / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology*; D002999:Clone Cells; D006224:Cricetinae; D003412:Cricetulus; D004848:Epithelium / Q000276:immunology; D005333:Fetus; D005434:Flow Cytometry; D007150:Immunohistochemistry; D008099:Liver / Q000166:cytology; D008221:Lymphoid Tissue / Q000276:immunology; D008565:Membrane Proteins / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D008970:Molecular Weight; D009924:Organ Culture Techniques; D017154:Stromal Cells / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology
D000911:Antibodies, Monoclonal; D008565:Membrane Proteins