CD4+ T cell acquisition of the bystander pMHC I colocalizing in the same immunological synapse comprising pMHC II and costimulatory CD40, CD54, CD80, OX40L, and 41BBL

Biochem Biophys Res Commun. 2007 Nov 3;362(4):822-8. doi: 10.1016/j.bbrc.2007.08.072. Epub 2007 Aug 22.


We previously showed that CD4+ T cells acquired peptide/major histocompatibility complex (pMHC) I and costimulatory molecules by dendritic cell (DC) activation. However, the molecular mechanism for pMHC I acquisition is unclear. In this study, by using a panel of engineered DC2.4 cells or incubation of these cells with Con A-stimulated CD4+ T cells, we conducted capping and synapse formation assay and examined them by confocal fluorescence microscopy. We demonstrated that (i) CD54 and CD80 colocalized with pMHC I/II in the same lipid rafts, whereas CD40, OX40L, and 41BBL localized in the lipid rafts but separately from pMHC I/II, and (ii) MHC I/II colocalized with the costimulatory molecules in the same synapse formed between a DC and a CD4+ T cell, leading to expression of the acquired bystander pMHC I on CD4+ T cells via internalization/recycling pathway. These results provide some useful information in composition and dynamics of immunological synapses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bystander Effect / immunology*
  • CD4-Positive T-Lymphocytes / immunology*
  • Cell Line
  • Cytokines / immunology*
  • Dendritic Cells / immunology*
  • Histocompatibility Antigens Class I / immunology*
  • Histocompatibility Antigens Class II / immunology*
  • Mice
  • Synapses / immunology*


  • Cytokines
  • Histocompatibility Antigens Class I
  • Histocompatibility Antigens Class II