Absence of B7-dependent responses in CD28-deficient mice

Immunity. 1994 Sep;1(6):501-8. doi: 10.1016/1074-7613(94)90092-2.


Costimulation of T cell proliferation can occur through the CD28 signal transduction pathway. In addition, other cell surface receptors, including the CD28 homolog CTLA-4, have been proposed to be capable of providing costimulatory signals. We have examined the response of CD28-deficient T cells to activation by a variety of agonists. We demonstrate that proliferation of CD28-deficient T cells in the presence of antigen-presenting cells or B7-1 transfectants is markedly reduced. Although CTLA-4 can be expressed on CD28-deficient T cells, we observed no B7-dependent costimulation in the absence of CD28. This data demonstrates that CD28 is the major B7-binding costimulatory ligand on T cells. Furthermore, our data suggest that CD28 is the primary, and perhaps exclusive, costimulatory receptor used by traditional antigen-presenting cells to augment the proliferation of antigen-activated T cells.

MeSH terms

  • Abatacept
  • Animals
  • Antigen-Presenting Cells / immunology
  • Antigens, CD
  • Antigens, Differentiation / immunology
  • B7-1 Antigen / immunology*
  • CD28 Antigens / immunology*
  • CD3 Complex / immunology
  • CHO Cells
  • CTLA-4 Antigen
  • Cricetinae
  • Cricetulus
  • Immunoconjugates*
  • Interleukin-2 / immunology
  • Lymphocyte Activation / immunology*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Signal Transduction / immunology
  • T-Lymphocytes / immunology*


  • Antigens, CD
  • Antigens, Differentiation
  • B7-1 Antigen
  • CD28 Antigens
  • CD3 Complex
  • CTLA-4 Antigen
  • Ctla4 protein, mouse
  • Immunoconjugates
  • Interleukin-2
  • Abatacept