title: Morphological change of CD4(+) T cell during contact with DC modulates T-cell activation by accumulation of F-actin in the immunology synapse.
abstract: BACKGROUND
  The changes in T-cell morphology during immunological synapse (IS) formation are essential for T-cell activation. Previous researches have shown that T cell changed from spherical to elongated and/or flattened during in contact with B cell. As most powerful antigen presenting cell, dendritic cell (DC) has a strong ability to activate T cells. However, the morphological change of T cell which contacts DC and the relationship between morphological change and T-cell activation are not very clear. Thus, we studied the morphological change of CD4(+) T cell during contact with DC.
  
  
  RESULTS
  Using live-cell imaging, we discovered diversity in the T-cell morphological changes during contact with DCs. The elongation-flattening of CD4(+) T cells correlated with a low-level Ca(2+) response and a loss of T-cell receptor (TCR) signalling molecules in the IS, including zeta-chain associated protein kinase 70 (ZAP-70), phospholipase C-γ (PLC-γ) and protein kinase C-θ (PKC-θ), whereas rounding-flattening correlated with sufficient CD4(+) T-cell activation. Different morphological changes were correlated with the different amount of accumulated filamentous actin (F-actin) in the IS. Disruption of F-actin by cytochalasin D impaired the morphological change and the localisation of calcium microdomains in the IS and decreased the calcium response in CD4(+) T cells.
  
  
  CONCLUSIONS
  Our study discovered the diversity in morphological change of T cells during contacted with DCs. During this process, the different morphological changes of T cells modulate T-cell activation by the different amount of F-actin accumulation in the IS, which controls the distribution of calcium microdomains to affect T-cell activation.
authors: Department of Immunology and Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China.|Biotherapy Research Centre, Fudan University, 138 Yixueyuan Road, Shanghai, 200032, China.
authors: Wei
authors: W
authors: Lin
authors: Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai, 200030, China.
authors: Yuanzhen
authors: Y
authors: Suo
authors: Department of Immunology and Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China.|Biotherapy Research Centre, Fudan University, 138 Yixueyuan Road, Shanghai, 200032, China.
authors: Yuting
authors: Y
authors: Deng
authors: Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai, 200030, China.
authors: Zhichao
authors: Z
authors: Fan
authors: Department of Immunology and Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China.|Biotherapy Research Centre, Fudan University, 138 Yixueyuan Road, Shanghai, 200032, China.
authors: Yijie
authors: Y
authors: Zheng
authors: Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai, 200030, China. xwei01@sjtu.edu.cn.
authors: Xunbin
authors: X
authors: Wei
authors: Department of Immunology and Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China. ywchu@shmu.edu.cn.|Biotherapy Research Centre, Fudan University, 138 Yixueyuan Road, Shanghai, 200032, China. ywchu@shmu.edu.cn.
authors: Yiwei
authors: Y
authors: Chu
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology; D020013:Calcium Signaling; D002450:Cell Communication; D048430:Cell Shape; D003713:Dendritic Cells / Q000166:cytology*; D054992:Immunological Synapses / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000276:immunology*; D021962:Membrane Microdomains / Q000378:metabolism; D008810:Mice, Inbred C57BL; D008928:Mitochondria / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism
chemical_list: D000199:Actins; D011948:Receptors, Antigen, T-Cell