Extrathymic maturation of alpha beta T cells from hemopoietic stem cells.
The object of the study was to determine whether alpha beta T cells can develop from hemopoietic stem cells in the absence of the thymus. C57BL/6 (Ly-5.1 and Thy-1.2) mice were thymectomized or sham-thymectomized at 4 wk of age, and received lethal whole body irradiation 2 wk later. These mice were reconstituted with an i.v. injection of 500 highly purified hemopoietic stem cells (Mac-1-, B220-, TER-119-, CD3-, CD4-, CD8-, Thy 1low, SCA-1+) obtained from the bone marrow of C57BL/6 (Ly-5.2 and Thy-1.1) donors. A similar percentage of Ly-5.2+ alpha beta T cells (donor) was found in the marrow of thymectomized recipients, sham-thymectomized recipients, and normal donor mice at least 3 mo after stem cell transplantation. The percentage of Ly-5.2+ alpha beta T cells in the spleens of sham-thymectomized and normal donor mice was similar. The percentage in the spleens of thymectomized recipients was reduced by about 50%, and approximately one-half of the latter T cells expressed the CD4-CD8- alpha beta+ phenotype. A purified population of Ly-5.2+ alpha beta- cells obtained from the marrow of thymectomized recipients was incubated in vitro for 48 h without exogenous growth factors. After the incubation procedure a proportion of the marrow cells acquired alpha beta TCR surface receptors. The results show that alpha beta T cells can develop from hemopoietic stem cells in the absence of the thymus.
Dejbakhsh-Jones
S
S
Department of Medicine, Stanford University School of Medicine, CA 94305, USA.
Jerabek
L
L
Weissman
I L
IL
Strober
S
S
D000818:Animals; D002454:Cell Differentiation; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013934:Thymectomy; D013950:Thymus Gland / Q000276:immunology*; D014916:Whole-Body Irradiation
D016693:Receptors, Antigen, T-Cell, alpha-beta