Premature TCRalphabeta expression and signaling in early thymocytes impair thymocyte expansion and partially block their development Journal Article


Authors: Lacorazza, H. D.; Tuček-Szabo, C.; Vasović, L. V.; Remus, K.; Nikolich-Žugich, J.
Article Title: Premature TCRalphabeta expression and signaling in early thymocytes impair thymocyte expansion and partially block their development
Abstract: In thymocyte ontogeny, Tcr-a genes rearrange after Tcr-b genes. TCRαβ transgenic (Tg) mice have no such delay, consequently expressing rearranged TCRαβ proteins early in the ontogeny. Such mice exhibit reduced thymic cellularity and accumulate mature, nonprecursor TCR+CD8-4- thymocytes, believed to be caused by premature Tg TCRαβ expression via unknown mechanism(s). Here, we show that premature expression of TCRαβ on early thymocytes curtails thymocyte expansion and impairs the CD8-4 → CD8+4+ transition. This effect is accomplished by two distinct mechanisms. First, the early formation of TCRαβ appears to impair the formation and function of pre-TCR, consistent with recently published results. Second, the premature TCRαβ contact with intrathymic MHC molecules further pronounces the block in proliferation and differentiation. These results suggest that the benefit of asynchronous Tcr-a and Tcr-b rearrangement is not only to minimize waste during thymopoiesis, but also to simultaneously allow proper expression/function of the pre-TCR and to shield CD8-4- thymocytes from TCRαβ signals that impair thymocyte proliferation and CD8-4- → CD8+4+ transition.
Keywords: signal transduction; controlled study; nonhuman; cd8 antigen; cell proliferation; animal cell; mouse; animals; mice; cell cycle; cell division; gene expression; cell differentiation; mice, inbred c57bl; transgenic mouse; mice, transgenic; t lymphocyte receptor beta chain; gene rearrangement; recombinant fusion proteins; genes, t-cell receptor beta; thymus gland; rna, messenger; membrane glycoproteins; stem cells; t-lymphocyte subsets; cd4 antigen; thymocyte; transgenes; receptors, antigen, t-cell, alpha-beta; ontogeny; receptors, interleukin-2; growth inhibitors; major histocompatibility antigen; priority journal; article; gene rearrangement, alpha-chain t-cell antigen receptor; genes, t-cell receptor alpha; gene rearrangement, beta-chain t-cell antigen receptor
Journal Title: Journal of Immunology
Volume: 166
Issue: 5
ISSN: 0022-1767
Publisher: The American Association of Immunologists, Inc  
Date Published: 2001-03-01
Start Page: 3184
End Page: 3193
Language: English
PUBMED: 11207271
PROVIDER: scopus
DOI: 10.4049/jimmunol.166.5.3184
DOI/URL:
Notes: Export Date: 21 May 2015 -- Source: Scopus
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  1. Ljiljana V Vasovic
    12 Vasovic
  2. Kristin E Remus
    7 Remus