Complement component 3 is required for optimal expansion of CD8 T cells during a systemic viral infection

J Immunol. 2003 Jan 15;170(2):788-94. doi: 10.4049/jimmunol.170.2.788.


In addition to its established role in innate immune mechanisms, complement component C3 is also of critical importance in B cell activation and T cell-dependent Ab responses. In this study, we have examined the requirement for C3 in the generation of primary CD8 T cell responses to an acute systemic viral infection. We compared Ag-specific CD8 T cell responses to lymphocytic choriomeningitis virus (LCMV) between wild-type (+/+) and C3-deficient (C3(-/-)) mice on both 129/B6 and B6 backgrounds. These studies revealed that C3 activity is required for optimal expansion of LCMV-specific effector CD8 T cells in an epitope-dependent fashion, which is influenced by the genetic background of the mice. Studies in complement receptor 1/2 (CR1/CR2)-deficient mice showed that regulation of LCMV-specific CD8 T cell responses by C3 is not dependent upon CR1/CR2. These findings may have implications in vaccine development, therapy of autoimmune diseases, and prevention of graft rejection.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acute Disease
  • Animals
  • CD8-Positive T-Lymphocytes / cytology
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / metabolism
  • CD8-Positive T-Lymphocytes / virology*
  • Cell Division / genetics
  • Cell Division / immunology
  • Cells, Cultured
  • Complement C3 / deficiency
  • Complement C3 / genetics
  • Complement C3 / physiology*
  • Epitopes, T-Lymphocyte / immunology
  • Lymphocyte Activation / genetics
  • Lymphocytic Choriomeningitis / genetics
  • Lymphocytic Choriomeningitis / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Receptors, Complement / deficiency
  • Receptors, Complement / genetics
  • Receptors, Complement 3d / deficiency
  • Receptors, Complement 3d / genetics


  • Complement C3
  • Epitopes, T-Lymphocyte
  • Receptors, Complement
  • Receptors, Complement 3d