Studies on the interdependence of gp39 and B7 expression and function during antigen-specific immune responses

Eur J Immunol. 1995 Feb;25(2):596-603. doi: 10.1002/eji.1830250243.


Interactions between T and B cells are dynamic and regulated by interacting receptor: co-receptors. Interactions between CD40 and its ligand, gp39, and the CD28/CTLA-4 and B7 family members play a decisive role in regulating the progression of cognate interactions. The interdependence of gp39-CD40 and CD28/CTLA-B7 expression and function was studied in vitro during an antigen-induced immune response using T cells from mice expressing a transgenic T cell receptor (TCR). gp39 was induced on pigeon cytochrome c (PCC)-transgenic T cells in the presence of antigen and antigen-presenting cells. The antigen-induced expression of gp39 on transgenic T cells was inhibited by antibodies to class II major histocompatibility complex, CD4 and LFA-1, but not by CTLA-4 Ig, anti-B7-1 or anti-B7-2. These data established that the antigen-induced expression of gp39 was not dependent on co-stimulation via CD28/CTLA-4. The addition of PCC also resulted in the modest expression of B7-1 and a more robust expression of B7-2 on the cognate B cells. The addition of anti-gp39 blocked the up-regulated expression of B7-1 and partially blocked the up-regulated expression of B7-2. The addition of anti-gp39 and anti-interleukin-4 inhibited antigen-induced expression of B7-2 on B cells to near background levels. Studies on the up-regulation of B7-1 and B7-2 on resting B cells showed that soluble gp39 up-regulated B7-1 and B7-2 expression on B cells. In addition, interleukin-4 and interferon-gamma up-regulated B7-2 expression on B cells. Taken together, these data demonstrate that the antigen-induced expression of gp39 is dependent on TCR-derived signals, yet independent of CD28/CTLA-4 co-stimulatory signals. Cognate interactions also resulted in the modest enhancement of B7-1 expression and a more profound expression of B7-2 which were completely or partially dependent on gp39-CD40 interactions.

MeSH terms

  • Abatacept
  • Amino Acid Sequence
  • Animals
  • Antigen-Presenting Cells / physiology
  • Antigens / immunology*
  • Antigens, CD*
  • Antigens, Differentiation / physiology
  • B7-1 Antigen / analysis*
  • B7-1 Antigen / physiology
  • B7-2 Antigen
  • CD4-Positive T-Lymphocytes / physiology
  • CD40 Ligand
  • CTLA-4 Antigen
  • Cells, Cultured
  • Immunoconjugates*
  • Lymphocyte Activation
  • Male
  • Membrane Glycoproteins / analysis*
  • Membrane Glycoproteins / physiology
  • Mice
  • Mice, Inbred C57BL
  • Molecular Sequence Data


  • Antigens
  • Antigens, CD
  • Antigens, Differentiation
  • B7-1 Antigen
  • B7-2 Antigen
  • CTLA-4 Antigen
  • Cd86 protein, mouse
  • Ctla4 protein, mouse
  • Immunoconjugates
  • Membrane Glycoproteins
  • CD40 Ligand
  • Abatacept