Доступ предоставлен для: Guest
Портал Begell Электронная Бибилиотека e-Книги Журналы Справочники и Сборники статей Коллекции
Critical Reviews™ in Immunology
Импакт фактор: 1.404 5-летний Импакт фактор: 3.347 SJR: 0.706 SNIP: 0.55 CiteScore™: 2.19

ISSN Печать: 1040-8401
ISSN Онлайн: 2162-6472

Том 40, 2020 Том 39, 2019 Том 38, 2018 Том 37, 2017 Том 36, 2016 Том 35, 2015 Том 34, 2014 Том 33, 2013 Том 32, 2012 Том 31, 2011 Том 30, 2010 Том 29, 2009 Том 28, 2008 Том 27, 2007 Том 26, 2006 Том 25, 2005 Том 24, 2004 Том 23, 2003 Том 22, 2002 Том 21, 2001 Том 20, 2000 Том 19, 1999 Том 18, 1998 Том 17, 1997 Том 16, 1996 Том 15, 1995 Том 14, 1994

Critical Reviews™ in Immunology

DOI: 10.1615/CritRevImmunol.v18.i4.40
pages 359-370

Positive and Negative Thymocyte Selection

Takashi Saito
Department of Molecular Genetics, Chiba University, Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
Norihiko Watanabe
Department of Molecular Genetics, Chiba University, Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan

Краткое описание

T cells differentiate from CD4-CD8- (DN) precursor to mature CD4+ or CD8+ (SP) thymocytes through the CD4+CD8+ (DP) stage. Immature thymocytes express pre-TCR complex composed of pTα and TCRβ chains, which plays a role in allelic exclusion of TCRβ and promotion from DN to DP transition. During the DP stage, thymocytes are subjected for selection, either expansion/differentiation into SP cells (positive selection) or deletion (negative selection). The level of TCR signals, which is mainly affected by the avidity between TCR and self-peptide/MHC and the contribution of coreceptors (CD4, CD8), determines the fate of thymocytes. The difference of avidity may result in distinct kinetics when signaling machinery assembles with TCR. As TCR signals increase either by high expression of TCR/coreceptors or higher avidity, the fate of thymocytes changes from default death (no selection) to positive selection and then negative selection. Although signaling pathways to discriminate these selections are largely unknown, ZAP-70 and Lck are important for both processes, whereas calcineurin and MARK pathway play crucial roles in positive selection. TCR signals also affect the CD4/CD8 lineage commitment. The requirements for the two lineages are different. Differentiation of CD4 SP thymocytes requires stronger TCR signals, while special signals such as Notch-mediated signal are necessary for development of CD8+ cells.

Ключевые слова: avidity, CD3ζ, , coreceptor, lineage commitment, peptide, TCR.

Articles with similar content:

Costimulation Signals for Memory CD8+ T Cells During Viral Infections
Critical Reviews™ in Immunology, Vol.29, 2009, issue 6
Peter D. Katsikis, Alina C. Boesteanu, Priyanka A. Duttagupta
Transcription Factor Network Regulating CD+CD8+ Thymocyte Survival
Critical Reviews™ in Immunology, Vol.31, 2011, issue 6
Yan Ding, Zuoming Sun, Jian Ma, Zhaofeng Huang, Huimin Xie, Xianfeng Fang, Ruiqing Wang
Immune Function of Thyroid Stimulating Hormone and Receptor
Critical Reviews™ in Immunology, Vol.21, 2001, issue 4
Heuy-Ching Wang, John R. Klein
CD4+ T Cells Orchestrate Both Amplification and Deletion of CD8+T Cells
Critical Reviews™ in Immunology, Vol.18, 1998, issue 6
Enza Piccolella, Loredana Frasca, Cinzia Piazza
CD40 and Dendritic Cell Function
Critical Reviews™ in Immunology, Vol.23, 2003, issue 1-2
Ranjeny Thomas, Brendan O'Sullivan