The peripheral T cell repertoire: independent homeostatic regulation of virgin and activated CD8+ T cell pools.
Mature T cells may be produced in the thymus, or by expansion in the periphery. While thymus output of virgin cells ensures repertoire diversity, peripheral expansion increases the size of rare clones, and thus the efficiency of immune responses. We studied the role of both phenomena in the generation of the CD8+ T cell pool using RAG-/- female mice expressing a transgenic T cell receptor specific for the male antigen; nude mice injected with peripheral T cells; and euthymic irradiated chimeras injected with bone marrow and mature T cells. Our results show that the total number of virgin and activated T cells, each constituting about half of the peripheral T cell pool, was regulated independently, revealing an efficient mechanism to maintain repertoire diversity while optimizing the immune response.
Tanchot
C
C
U.345 INSERM, Institut Necker, Paris, France.
Rocha
B
B
D000486:Allergy and Immunology / Q000592:standards; D000818:Animals; D001853:Bone Marrow / Q000276:immunology; D016827:CD8 Antigens / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002352:Carrier Proteins / Q000276:immunology; D002465:Cell Movement / Q000276:immunology*; D005260:Female; D018960:Hyaluronan Receptors; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D011956:Receptors, Cell Surface / Q000276:immunology; D016201:Receptors, Lymphocyte Homing / Q000276:immunology; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology / Q000378:metabolism
D016827:CD8 Antigens; D002352:Carrier Proteins; D018960:Hyaluronan Receptors; D011956:Receptors, Cell Surface; D016201:Receptors, Lymphocyte Homing