Accessory cell-derived signals required for T cell activation

Immunol Res. 1993;12(1):48-64. doi: 10.1007/BF02918368.


Various populations of accessory cells differ in their abilities to function as effective antigen-presenting cells (APC) and stimulate CD4+ T cells to produce interleukin-2. Three important factors directly related to APC potency are the expression of class II major histocompatibility complex molecules and the ability to present peptide antigens to the T cell antigen receptor, the expression of costimulatory ligands which deliver important activation signals independent of T cell receptor occupancy and the expression of adhesion molecules which promote conjugate formation so that these activation signals can be effectively delivered to the T cells. The relative importance of these accessory cell functions in T cell activation will be discussed, with an emphasis on costimulation and the CD28/B7 receptor/ligand pair. The consequence of inadequate costimulation by an otherwise effective APC in inducing T cell anergy will also be discussed.

Publication types

  • Review

MeSH terms

  • Animals
  • Antigen-Presenting Cells / immunology*
  • Antigens / immunology
  • Antigens / metabolism
  • Antigens, CD / physiology
  • Antigens, Differentiation, T-Lymphocyte / physiology
  • CD28 Antigens
  • CD4-Positive T-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / metabolism
  • CHO Cells
  • Cell Adhesion Molecules / physiology
  • Cell Line
  • Chlorocebus aethiops
  • Cricetinae
  • Cytokines / physiology
  • Histocompatibility Antigens Class II / immunology
  • Humans
  • Immune Tolerance
  • Intercellular Adhesion Molecule-1
  • Interleukin-2 / biosynthesis
  • Lymphocyte Activation*
  • Lymphocyte Function-Associated Antigen-1 / physiology
  • Mice
  • Receptors, Antigen, T-Cell / immunology
  • Signal Transduction*


  • Antigens
  • Antigens, CD
  • Antigens, Differentiation, T-Lymphocyte
  • CD28 Antigens
  • Cell Adhesion Molecules
  • Cytokines
  • Histocompatibility Antigens Class II
  • Interleukin-2
  • Lymphocyte Function-Associated Antigen-1
  • Receptors, Antigen, T-Cell
  • Intercellular Adhesion Molecule-1