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Blood, 15 April 2005, Vol. 105, No. 8, pp. 3238-3246. Prepublished online as a Blood First Edition Paper on January 6, 2005; DOI 10.1182/blood-2004-08-3236. This Article Full Text (PDF) Supplemental Figures All Versions of this Article: 2004-08-3236v1 105/8/3238    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Zhou, J. Articles by Sabzevari, H. Search for Related Content PubMed PubMed Citation Articles by Zhou, J. Articles by Sabzevari, H. Social Bookmarking                   What's this?  Previous Article  |  Next Article  Submitted August 20, 2004 Accepted December 21, 2004 Physiological relevance of Antigen Presentosome (APS), an acquired MHC/costimulatory complex, in the sustained activation of CD4+ T cells in the absence of APCs Jun Zhou, Yutaka Tagaya, Roshanak Tolouei-Semnani, Jeffrey Schlom*, and Helen Sabzevari Laboratory of Tumor Immunology and Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA Metabolism Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA * Corresponding author; email: js141c{at}nih.gov. T-cell interaction with antigen presenting cells (APCs) results in activation and clonal expansion of naive T cells. CD80 expression/acquisition in T cells has been implicated in disease processes in patients with rheumatoid arthritis and multiple myeloma, and patients infected with HIV. Our previous data indicate that antigen-specific activation of naive T cells results in T-cell acquisition of CD80 molecules from APCs. However, the functional relevance of the acquired CD80 by T cells in signal pathways has remained unresolved. This study aims to define for the first time the role of acquired CD80 in T-cell clonal expansion. We demonstrate: (1) T cells, upon CD80 acquisition, sustain their proliferative response in the absence of APCs; (2) T cells that acquire CD80 sustain the activity of transcriptional factors such as NFB and AP1 for 24 hours post-separation from APCs and upregulate Stat5 in the absence of APCs or exogenous signal 1; and (3) maintenance of these signals results in unique cytokine production. Collectively, our data support the unique concept that naive T cells sustain their activation by removing "antigen presentasome" (APS, e.g., antigen presenting complex) from APCs, thereby releasing the constraint of APC requirement for further activation. CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this? This article has been cited by other articles: C. S. Umeshappa, H. Huang, Y. Xie, Y. Wei, S. J. Mulligan, Y. Deng, and J. Xiang CD4+ Th-APC with Acquired Peptide/MHC Class I and II Complexes Stimulate Type 1 Helper CD4+ and Central Memory CD8+ T Cell Responses J. Immunol., January 1, 2009; 182(1): 193 - 206. [Abstract] [Full Text] [PDF] A. Busch, T. Quast, S. Keller, W. Kolanus, P. Knolle, P. Altevogt, and A. Limmer Transfer of T Cell Surface Molecules to Dendritic Cells upon CD4+ T Cell Priming Involves Two Distinct Mechanisms J. Immunol., September 15, 2008; 181(6): 3965 - 3973. [Abstract] [Full Text] [PDF] J. Helft, A. Jacquet, N. T. Joncker, I. Grandjean, G. Dorothee, A. Kissenpfennig, B. Malissen, P. Matzinger, and O. Lantz Antigen-specific T-T interactions regulate CD4 T-cell expansion Blood, August 15, 2008; 112(4): 1249 - 1258. [Abstract] [Full Text] [PDF] S. Hao, J. Yuan, and J. Xiang Nonspecific CD4+ T cells with uptake of antigen-specific dendritic cell-released exosomes stimulate antigen-specific CD8+ CTL responses and long-term T cell memory J. Leukoc. Biol., October 1, 2007; 82(4): 829 - 838. [Abstract] [Full Text] [PDF] R. A. Reisfeld Memory T cells: death by acquisition Blood, March 15, 2007; 109(6): 2269 - 2270. [Full Text] [PDF] S. Mostbock, M. Catalfamo, Y. Tagaya, J. Schlom, and H. Sabzevari Acquisition of antigen presentasome (APS), an MHC/costimulatory complex, is a checkpoint of memory T-cell homeostasis Blood, March 15, 2007; 109(6): 2488 - 2495. [Abstract] [Full Text] [PDF] J. LeMaoult, J. Caumartin, M. Daouya, B. Favier, S. L. Rond, A. Gonzalez, and E. D. Carosella Immune regulation by pretenders: cell-to-cell transfers of HLA-G make effector T cells act as regulatory cells Blood, March 1, 2007; 109(5): 2040 - 2048. [Abstract] [Full Text] [PDF]

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