The expanding B7 superfamily: increasing complexity in costimulatory signals regulating T cell function

Nat Immunol. 2001 Mar;2(3):203-9. doi: 10.1038/85251.


Upon encounter with specific antigen, naïveT helper precursor (THP) cells become activated. This event is regulated not only by engagement of the T cell receptor (TCR) with peptide presented in the context of major histocompatibility complex (MHC) class II molecules but by a number of costimulatory signals. CD28 engagement by B7-1 and B7-2 on resting THP cells provides a critical signal for initial cell cycle progression, interleukin 2 production and clonal expansion. However, largely as a consequence of the unraveling of the human genome, it is becoming clear that B7-1 and B7-2 are part of a larger family T of related counter-receptors that play an essential role in regulating the fate of primed, rather then resting,THP cells. These molecules play an important sequential role and act, together with B7-1- and B7-2-primed T cells, in the acquisition of effector function and/or tolerance induction.

Publication types

  • Review

MeSH terms

  • Abatacept
  • Animals
  • Antigens, CD / genetics
  • Antigens, CD / immunology
  • Antigens, Differentiation / immunology
  • B7-1 Antigen / genetics
  • B7-1 Antigen / immunology*
  • B7-2 Antigen
  • CD28 Antigens / immunology
  • CTLA-4 Antigen
  • Cytokines / biosynthesis
  • Forecasting
  • Humans
  • Immunoconjugates*
  • Inducible T-Cell Co-Stimulator Ligand
  • Lymphocyte Activation*
  • Lymphocyte Cooperation
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / immunology
  • Mice
  • Models, Immunological
  • Phylogeny
  • Protein Isoforms / genetics
  • Protein Isoforms / immunology
  • T-Lymphocytes, Helper-Inducer / immunology*


  • Antigens, CD
  • Antigens, Differentiation
  • B7-1 Antigen
  • B7-2 Antigen
  • CD28 Antigens
  • CD86 protein, human
  • CTLA-4 Antigen
  • CTLA4 protein, human
  • Cd86 protein, mouse
  • Ctla4 protein, mouse
  • Cytokines
  • Immunoconjugates
  • Inducible T-Cell Co-Stimulator Ligand
  • Membrane Glycoproteins
  • Protein Isoforms
  • Abatacept