Preferential expression of fibronectin receptors on immature thymocytes.
Fibronectin-adherent (FNR+) thymocytes are enriched for immature (CD4-8-) and large (CD4+8+) cells, and depleted of mature (CD4-8+ and CD4+8-) and nonmature small (CD4+8+) cells. Among purified CD4-8- thymocytes, cells with the surface marker J11d and the IL-2 receptor, which can give rise to all other thymocyte subsets, showed selective attachment to fibronectin. Analysis of FNR+ thymocytes showed that such cells are greatly enriched for cells in cycle. Additionally, FNR+ cells expressed low levels of T cell receptor. These results suggest a role for the fibronectin receptor during the early, proliferative phase of thymocyte differentiation. The data suggest that loss of the fibronectin receptor is a hallmark of cells that have become committed either to functional maturation or to programmed cell death.
Cardarelli
P M
PM
Cancer Research Center, La Jolla Cancer Research Foundation, California 92037.
Crispe
I N
IN
Pierschbacher
M D
MD
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D002448:Cell Adhesion; D002453:Cell Cycle; D002454:Cell Differentiation; D005353:Fibronectins / Q000502:physiology*; D005434:Flow Cytometry; D007158:Immunologic Techniques; D051379:Mice; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D016693:Receptors, Antigen, T-Cell, alpha-beta; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic / Q000502:physiology*; D013601:T-Lymphocytes / Q000145:classification / Q000502:physiology*; D013950:Thymus Gland / Q000166:cytology*
D000945:Antigens, Differentiation, T-Lymphocyte; D005353:Fibronectins; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic