Extending the B7 (CD80) gene family

Protein Sci. 1994 Aug;3(8):1341-3. doi: 10.1002/pro.5560030820.


B7-1 and B7-2 are members of the immunoglobulin superfamily (IgSF) and important regulators of T cell-mediated immune responses. Despite sharing only limited sequence identity, B7-1 and B7-2 bind common receptors, CD28 and CTLA-4, on T cells and have similar functional properties. We have found that the extracellular V (ariable)-like domains of B7-1 and B7-2 share significant sequence similarities with 3 major histocompatibility complex (MHC)-encoded members of the IgSF: butyrophilin, myelin/oligodendrocyte glycoprotein, and the chicken MHC molecule, B-G. This raises the question whether there is an evolutionary link between the MHC, which encodes molecules regulating the antigen specificity of T lymphocyte responses, and B7 molecules, which co-stimulate these responses in antigen-nonspecific fashion.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Antigens, CD*
  • B7-1 Antigen / chemistry
  • B7-1 Antigen / genetics*
  • B7-2 Antigen
  • Butyrophilins
  • Consensus Sequence
  • Membrane Glycoproteins / chemistry
  • Molecular Sequence Data
  • Myelin Proteins / chemistry
  • Myelin-Associated Glycoprotein*
  • Myelin-Oligodendrocyte Glycoprotein
  • Proteins / chemistry
  • Sequence Alignment
  • T-Lymphocytes / immunology


  • Antigens, CD
  • B-G antigen, Gallus gallus
  • B7-1 Antigen
  • B7-2 Antigen
  • Butyrophilins
  • Membrane Glycoproteins
  • Myelin Proteins
  • Myelin-Associated Glycoprotein
  • Myelin-Oligodendrocyte Glycoprotein
  • Proteins

Associated data

  • GENBANK/L25259
  • GENBANK/L25606
  • GENBANK/M27533
  • GENBANK/M61863
  • GENBANK/M99485
  • GENBANK/X60958
  • SWISSPROT/P18892