We have previously isolated, and characterized in vitro, two subsets of CD4hi T cell receptor (TCR)hi single positive (SP) thymocytes: CD8- and CD8lo. In this report, we have analyzed phenotypic, functional, and developmental characteristics of these "late" CD4hi SP thymocyte subsets. The TCRhi phenotype and the elimination of T cells expressing TCR V beta segments reactive with endogenous mouse mammary tumor virus (MMTV) products suggested that both subsets had undergone positive and negative selection. CD8-4hi thymocytes were functional, as judged by their ability to: (a) induce lethal graft versus host disease (GVHD); (b) survive and expand in peripheral lymphoid organs; and (c) proliferate, rather than undergo apoptosis, in response to in vitro TCR cross-linking. By contrast, CD8lo4hi cells could not induce GVHD, were unable to expand (and perhaps even survive) in peripheral organs and underwent apoptosis upon TCR cross-linking. However, when reintroduced into the thymus, these cells matured into functional, long-lived CD8-4hi lymphocytes. These results document an obligatory requirement for the thymic microenvironment in the final maturation of the majority of CD4hi SP postselection thymocytes, and demonstrate the existence of a previously unrecognized control point in T cell development.
Article|
January 01 1995
The majority of postselection CD4+ single-positive thymocytes requires the thymus to produce long-lived, functional T cells.
R Dyall,
R Dyall
Laboratory of T Cell Development, Immunology Program, Memorial Sloan-Kettering Cancer Center, New York 10021.
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J Nikolić-Zugić
J Nikolić-Zugić
Laboratory of T Cell Development, Immunology Program, Memorial Sloan-Kettering Cancer Center, New York 10021.
Search for other works by this author on:
R Dyall
Laboratory of T Cell Development, Immunology Program, Memorial Sloan-Kettering Cancer Center, New York 10021.
J Nikolić-Zugić
Laboratory of T Cell Development, Immunology Program, Memorial Sloan-Kettering Cancer Center, New York 10021.
Online ISSN: 1540-9538
Print ISSN: 0022-1007
J Exp Med (1995) 181 (1): 235–245.
Citation
R Dyall, J Nikolić-Zugić; The majority of postselection CD4+ single-positive thymocytes requires the thymus to produce long-lived, functional T cells.. J Exp Med 1 January 1995; 181 (1): 235–245. doi: https://doi.org/10.1084/jem.181.1.235
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