Clonable progenitors committed to the T lymphocyte lineage in the mouse bone marrow; use of an extrathymic pathway.
We searched for clonable committed T cell progenitors in the adult mouse bone marrow and isolated rare (approximately 0.05%) cells with the Thy-1hiCD2-CD16+CD44hiCD25-Lin- phenotype. In vivo experiments showed that these cells were progenitors committed only to reconstituting the T cell lineage of irradiated Ly5 congenic hosts. Reconstitution of the thymus was minimal compared with that of the bone marrow, spleen, and lymph nodes. At limiting dilutions, donor T cell reconstitution of the spleen frequently occurred without detectable donor cells in the thymus. Progenitors were capable of rapidly reconstituting athymic hosts. In conclusion, the clonable bone marrow progenitors were capable of T cell reconstitution predominantly by means of an extrathymic pathway.
Dejbakhsh-Jones
S
S
Department of Medicine, Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Garcia-Ojeda
M E
ME
Chatterjea-Matthes
D
D
Zeng
D
D
Strober
S
S
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001854:Bone Marrow Cells / Q000276:immunology* / Q000528:radiation effects; D002478:Cells, Cultured; D002999:Clone Cells; D005434:Flow Cytometry; D015329:Gene Rearrangement, T-Lymphocyte; D015332:Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D006412:Hematopoietic Stem Cells / Q000276:immunology* / Q000528:radiation effects; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D016133:Polymerase Chain Reaction; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D013997:Time Factors; D014916:Whole-Body Irradiation
D000945:Antigens, Differentiation, T-Lymphocyte