Conversion of naive T cells to a memory-like phenotype in lymphopenic hosts is not related to a homeostatic mechanism that fills the peripheral naive T cell pool.
To examine directly whether a limited number of naive T cells transferred to lymphopenic hosts can truly fill the peripheral naive T cell pool, we compared the expansion and phenotype of naive T cells transferred to three different hosts, namely recombination-activating gene-deficient mice, CD3epsilon-deficient mice, and irradiated normal mice. In all three recipients, the absolute number of recovered cells was much smaller than in normal mice. In addition, transferred naive T cells acquired a memory-like phenotype that remained stable with time. Finally, injected cells were rapidly replaced by host thymic migrants in irradiated normal mice. Only continuous output of naive T cells by the thymus can generate a full compartment of truly naive T cells. Thus, conversion of naive T cells to a memory-like phenotype in lymphopenic hosts is not related to a homeostatic mechanism that fills the peripheral naive T cell pool.
Tanchot
Corinne
C
Institut National de la Santé et de la Recherche Médicale, Unité 345, Faculté de Médecine Necker-Enfants Malades, Université René Descartes, 156 rue de Vaugirard, F-75730 Paris Cedex 15, France.
Le Campion
Armelle
A
Martin
Bruno
B
Léaument
Sandrine
S
Dautigny
Nicole
N
Lucas
Bruno
B
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000528:radiation effects / Q000637:transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology; D006706:Homeostasis / Q000235:genetics / Q000276:immunology* / Q000528:radiation effects; D007156:Immunologic Memory / Q000235:genetics / Q000528:radiation effects; D016130:Immunophenotyping; D007399:Interphase / Q000235:genetics / Q000276:immunology* / Q000528:radiation effects; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology / Q000637:transplantation; D008231:Lymphopenia / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D051379:Mice; D008805:Mice, Inbred A; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D011828:Radiation Chimera / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000637:transplantation; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000528:radiation effects; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology