title: Homeostatic properties and phenotypic maturation of murine CD4+ pre-thymic emigrants in the thymus.
abstract: After a tightly regulated developmental program in the thymus, "mature" single positive (SP) thymocytes leave the thymus and enter the periphery. These newly arrived recent thymic emigrants (RTEs) are phenotypically and functionally immature, and will complete a dynamic maturation in the peripheral lymphoid organs before being licensed to be resident naïve T cells. To study the early events occurring in the RTE maturation process, we identified the phenotype of CD4(+) pre-RTEs, a population of CD4(+) SP thymocytes that have acquired the thymus egress capability. Compared to peripheral naïve T cells, CD4(+) pre-RTEs displayed superior survival capability in lymphoreplete mice and faster proliferation under lymphopenic condition. The differences in Bcl2/Bim expression and/or heightened IL-7 signaling pathway may account for the pre-RTEs' better responsiveness to homeostatic signals. Qa2, the expression of which indicates the phenotypic maturation of SPs and RTEs, was found to be upregulated in CD4(+) pre-RTEs in thymic perivascular space. Migratory dendritic cells that surround this region contribute to Qa2 expression in pre-RTEs. The dendritic cell-driven Qa2 induction of CD4(+) pre-RTEs is independent of MHC class II and Aire molecules.
authors: Key Laboratory of Medical Immunology, Ministry of Health, Department of Immunology, Peking University Health Science Center, Beijing, China.
authors: Jie
authors: J
authors: Dong
authors: Yu
authors: Y
authors: Chen
authors: Xi
authors: X
authors: Xu
authors: Rong
authors: R
authors: Jin
authors: Fei
authors: F
authors: Teng
authors: Fan
authors: F
authors: Yan
authors: Hui
authors: H
authors: Tang
authors: Pingping
authors: P
authors: Li
authors: Xiuyuan
authors: X
authors: Sun
authors: Yan
authors: Y
authors: Li
authors: Hounan
authors: H
authors: Wu
authors: Yu
authors: Y
authors: Zhang
authors: Qing
authors: Q
authors: Ge
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D049109:Cell Proliferation; D002470:Cell Survival; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology; D006706:Homeostasis / Q000276:immunology*; D037181:Lectins, C-Type / Q000378:metabolism; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D010641:Phenotype; D015398:Signal Transduction / Q000276:immunology; D060168:Thymocytes / Q000166:cytology / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology*; D015854:Up-Regulation; D000099192:CD69 Antigens
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D037181:Lectins, C-Type; D000099192:CD69 Antigens