Cd5 (OKT1) augments CD3-mediated intracellular signaling events in human T lymphocytes

Academic Article


  • CD5 is expressed on thymocytes, all mature T cells, and a subset of mature B cells, and probably contributes to T-cell-B-cell adhesion. We assessed whether CD5-crosslinking by mAb augments T-cell stimulation. Plate-bound anti-CD5 or anti-CD3 mAb alone had no effect on any of the assessed activation parameters of resting T cells. However, concomitant signaling through both CD5 and CD3 by plate-bound antibodies resulted in marked increases in T-cell surface CD69 expression and T-cell metabolism, as assessed by the T cell's ability to reduce 3-(4,5dimethylthiazol-2-yl)-5-(3-carboxylmethoxyphenyl)-2-(4-sulphophenyl)- 2H-tetrazolium (MTS) to formazen. In addition, simultaneous cross-linking of CD5 and CD3 caused a significant (p < 0.001) increase in phosphatidylinositol hydrolysis in resting T cells compared to stimulation with anti-CD3 mAb alone or anti-CD3 mAb plus anti-CD5 isotype control antibody. These results indicate that CD5 augments signaling through CD3 and consequently functions as a costimulatory molecule for resting T cells.
  • Authors

    Published In

  • Inflammation  Journal
  • Digital Object Identifier (doi)

    Author List

  • Tran TS; Jamulitrat S; Chongsuvivatwong V; Geater A
  • Start Page

  • 215
  • End Page

  • 221
  • Volume

  • 25
  • Issue

  • 4