International Immunology Advance Access originally published online on September 27, 2006
International Immunology 2006 18(11):1615-1625; doi:10.1093/intimm/dxl095
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Analyses of TCR clustering at the T cellantigen-presenting cell interface and its impact on the activation of naive CD4+ T cells
1 Center for Immunology, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390-9093, USA
2 Immunology Service, University Hospital Virgen de la Arrixaca, El Palmer, Murcia, Spain
3 Department of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080, USA
4 Cancer Immunobiology Center, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390-8576, USA
Correspondence to: E. S. Ward; E-mail: sally.ward{at}utsouthwestern.edu
The role of micrometer-scale clustering of TCRs at the T cellantigen-presenting cell (APC) interface in T cell activation is an area of active investigation. Here we have investigated the impact of variations in the extent of TCR clustering on the activation of naive CD4+ T cells. These T cells are derived from transgenic (tg) mice expressing TCRs (172.10 and 1934.4) specific for the N-terminal nonapeptide of MBP bound to I-Au, and are associated with murine experimental autoimmune encephalomyelitis (EAE). The 172.10 TCR has a
4-fold higher affinity for antigen relative to the 1934.4 TCR, allowing us to compare the properties of two tg T cells of different avidities. We observe that variations in large-scale TCR clustering at the T cellAPC interface do not correlate well with the extent of activation (CD25 or CD69 up-regulation and IL-2 or IFN-
production). Efficient activation can also be achieved in the absence of micrometer-scale TCR clustering, indicating that this is not a prerequisite for the effective stimulation of naive T cells.
Keywords: autoimmunity, experimental autoimmune encephalomyelitis, naive T cell activation, peptideMHC class II