Characterization of a cell surface-expressed disulfide-linked dimer involved in murine T cell activation

J Immunol. 1988 Jul 15;141(2):369-76.


We have produced a hamster mAb, H1.2F3, which was derived by immunization with a murine TCR-gamma delta + epidermal T cell line. H1.2F3 immunoprecipitates a cell surface-expressed disulfide-linked dimer that has a m.w. of 85,000 under non-reducing conditions and consists of subunits of 35,000 to 39,000 m.w. This dimer is distinct from the CD3-associated TCR-gamma delta complex (CD3/TCR), inasmuch as H1.2F3 does not co-precipitate or co-modulate with the CD3/TCR complex and recognizes an Ag with a single-peptide backbone of 22,000 m.w. after N-Glycanase treatment. H1.2F3 is weakly reactive with a small percentage of cells from unfractionated thymus, spleen, or lymph node, but reactivity with both T and B lymphocytes is markedly enhanced by a brief period of stimulation with Con A or PMA in vitro. This enhancement requires de novo protein synthesis. Enhanced expression of the H1.2F3 Ag can also be induced in vivo by injection of Con A or anti-CD3. H1.2F3 is a potent stimulator of T, but not B, cell proliferation in the presence of PMA and FcR-bearing accessory cells. These functional and biochemical studies strongly suggest that the Ag recognized by H1.2F3 is the murine homologue of the human CD28 Ag recognized by mAb 9.3.

MeSH terms

  • Aging
  • Animals
  • Antibodies, Monoclonal / biosynthesis
  • Antibodies, Monoclonal / physiology
  • Antigen-Presenting Cells / immunology
  • Antigens, Surface / immunology
  • Antigens, Surface / isolation & purification*
  • Cricetinae
  • Disulfides*
  • Lymphocyte Activation*
  • Mice
  • Mice, Inbred C3H
  • Molecular Weight
  • Protein Conformation
  • Structure-Activity Relationship
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism
  • T-Lymphocytes / physiology
  • Tetradecanoylphorbol Acetate / pharmacology
  • Tumor Necrosis Factor Receptor Superfamily, Member 7


  • Antibodies, Monoclonal
  • Antigens, Surface
  • Disulfides
  • Tumor Necrosis Factor Receptor Superfamily, Member 7
  • Tetradecanoylphorbol Acetate