Intrathymically expressed c-kit ligand (stem cell factor) is a major factor driving expansion of very immature thymocytes in vivo.
To investigate the role of the receptor-type tyrosine kinase, c-kit and its ligand, stem cell factor (SCF) in T cell development, we analyzed c-kit (W/W) and SCF (SI/SI) deficient mice. We also engrafted wild-type or SCF-deficient fetal thymi onto wild-type recipient mice and analyzed the rate of proliferation by in vivo bromodeoxyuridine labeling. The results show that the most immature thymocyte compartment defined as CD3-CD4-CD8- is significantly reduced in SI/SI grafts and W/W thymi compared with wild-type counterparts. Also, the expansion rate of these immature thymocytes in SI/SI graft is reduced by -50%. These experiments provide direct evidence for an important role for c-kit-SCF interactions in expansion of very early thymocytes.
Rodewald
H R
HR
Basel Institute for Immunology, Switzerland.
Kretzschmar
K
K
Swat
W
W
Takeda
S
S
D000818:Animals; D001483:Base Sequence; D001973:Bromodeoxyuridine / Q000378:metabolism; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D002465:Cell Movement; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D019089:Stem Cell Factor / Q000235:genetics / Q000502:physiology*; D013601:T-Lymphocytes / Q000502:physiology*
D015704:CD4 Antigens; D016827:CD8 Antigens; D019089:Stem Cell Factor; D001973:Bromodeoxyuridine