title: Peripheral T cell lymphopenia and concomitant enrichment in naturally arising regulatory T cells: the case of the pre-Talpha gene-deleted mouse.
abstract: In pre-Talpha (pTalpha) gene-deleted mice, the positively selectable CD4+ CD8+ double-positive thymocyte pool is only 1% that in wild-type mice. Consequently, their peripheral T cell compartment is severely lymphopenic with a concomitant increase in proportion of CD25+ FoxP3+ regulatory T cells. Using mixed bone marrow chimeras, where thymic output was 1% normal, the pTalpha(-/-) peripheral T cell phenotype could be reproduced with normal cells. In the pTalpha(-/-) thymus and peripheral lymphoid organs, FoxP3+ CD4+ cells were enriched. Parabiosis experiments showed that many pTalpha(-/-) CD4+ single-positive thymocytes represented recirculating peripheral T cells. Therefore, the enrichment of FoxP3+ CD4+ single-positive thymocytes was not solely due to increased thymic production. Thus, the pTalpha(-/-) mouse serves as a model system with which to study the consequences of chronic decreased thymic T cell production on the physiology of the peripheral T cell compartment.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale Unité 548, Commissariat à l'Energie Atomique-Grenoble, Grenoble, France.
authors.forename: Nabil
authors.initials: N
authors.lastname: Bosco
authors.forename: Fabien
authors.initials: F
authors.lastname: Agenes
authors.forename: Antonius G
authors.initials: AG
authors.lastname: Rolink
authors.forename: Rhodri
authors.initials: R
authors.lastname: Ceredig
mesh_terms: D000818:Animals; D016026:Bone Marrow Transplantation; D008231:Lymphopenia / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout; D010227:Parabiosis; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics*; D016176:T-Lymphocyte Subsets / Q000166:cytology*; D013601:T-Lymphocytes / Q000166:cytology*; D050378:T-Lymphocytes, Regulatory / Q000166:cytology*; D013950:Thymus Gland / Q000166:cytology; D018183:Transplantation Chimera
chemical_list: D016693:Receptors, Antigen, T-Cell, alpha-beta