Interleukin 7 induces preferential expansion of V beta 8.2+CD4-8- and V beta 8.2+CD4+8- murine thymocytes positively selected by class I molecules.
We analyzed the phenotype and V beta-T cell receptor (TCR) repertoire, together with interleukin 7 receptor (IL-7R) expression in unfractionated thymocytes stimulated in vitro with IL-7. This culture system results in a specific proliferation of mature thymocytes belonging to the CD3+CD4-, CD4+8-, and CD4-8+ subsets. IL-7 induced a preferential expansion of V beta 8.2+CD4-8- and V beta 8.2+CD4-8- thymocytes. This phenomenon is not observed in beta 2-microglobulin-deficient mice, showing that a fraction of CD4+8- thymocytes, enriched in V beta 8.2+ cells, is selected by class I molecules in normal mice, as are a large proportion of CD4-8- alpha beta TCR+ thymocytes. Our findings also establish that IL-7 plays a major role in the expansion of rare thymocyte subsets, which could exert important functions in inflammatory and immune responses.
Vicari
A
A
INSERM U345, Institut Necker, Paris, France.
de Moraes
M do C
Mdo C
Gombert
J M
JM
Dy
M
M
Penit
C
C
Papiernik
M
M
Herbelin
A
A
D000818:Animals; D015704:CD4 Antigens / Q000276:immunology*; D016827:CD8 Antigens / Q000276:immunology*; D002478:Cells, Cultured; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D015851:Interleukin-7 / Q000502:physiology*; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D010641:Phenotype; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology*; D018123:Receptors, Interleukin / Q000378:metabolism; D020395:Receptors, Interleukin-7; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology; D001613:beta 2-Microglobulin / Q000276:immunology
D015704:CD4 Antigens; D016827:CD8 Antigens; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D015851:Interleukin-7; D016693:Receptors, Antigen, T-Cell, alpha-beta; D018123:Receptors, Interleukin; D020395:Receptors, Interleukin-7; D001613:beta 2-Microglobulin