4-1BBL costimulation retrieves CD28 expression in activated T cells

Cell Immunol. 2009;256(1-2):39-46. doi: 10.1016/j.cellimm.2009.01.003. Epub 2009 Feb 12.


Binding of CD80/86 to CD28 is regarded as the main T cell costimulatory interaction. However, CD28 downregulates soon after T cell activation. To investigate potential cross-interaction between CD137 (4-1BB) and CD28, we stimulated T cells with anti-CD3 in the presence of A549 lung carcinoma cells expressing CD80/CD86 and 4-1BBL molecules, transduced into the cells using recombinant non-replicating adenoviruses. Following initial T cell proliferation, the proportion of CD28(+) cells in both CD4(+) and CD8(+) populations was rapidly reduced by CD80/86 costimulation, whereas cultures costimulated with just 4-1BBL continued to express CD28. CD28 was also downregulated in cultures costimulated with both CD80/86 and 4-1BBL. Interestingly, in cells costimulated with CD80/86 that had downregulated CD28 expression and ceased to proliferate, reactivation of proliferation by 4-1BBL costimulation also restored their CD28 expression. These findings show a positive effect of CD137 signalling on CD28 expression, similar to the effect of CD28 engagement on 4-1BB expression during the initial phases of T cell activation. Moreover, they point to the importance of signals through 4-1BB for the purposes of ex-vivo T cell activation and expansion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 4-1BB Ligand / genetics
  • 4-1BB Ligand / metabolism*
  • Adenoviridae / genetics
  • B7-1 Antigen / genetics
  • B7-1 Antigen / metabolism
  • B7-2 Antigen / genetics
  • B7-2 Antigen / metabolism
  • CD28 Antigens / metabolism*
  • CD3 Complex / metabolism
  • CD4-Positive T-Lymphocytes / cytology
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / cytology
  • CD8-Positive T-Lymphocytes / immunology
  • Cell Line, Tumor
  • Cell Proliferation
  • Genetic Vectors
  • Humans
  • In Vitro Techniques
  • Lymphocyte Activation
  • T-Lymphocytes / cytology
  • T-Lymphocytes / immunology*
  • Transduction, Genetic


  • 4-1BB Ligand
  • B7-1 Antigen
  • B7-2 Antigen
  • CD28 Antigens
  • CD3 Complex
  • CD86 protein, human