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Role of cyclin kinase inhibitor p21 in systemic autoimmunity

M L Santiago-Raber1, B R Lawson, W Dummer

  • 1Department of Immunology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.

Journal of Immunology (Baltimore, Md. : 1950)
|September 21, 2001
PubMed

Insights

The cyclin-dependent kinase inhibitor p21 (p21) deficiency enhances T cell activation and proliferation, potentially contributing to autoimmunity. However, p21-deficient mice develop only mild autoimmune symptoms, not a full lupus-like disease.

Area of Science:

  • Immunology
  • Cell Biology
  • Autoimmunity

Background:

  • The cyclin-dependent kinase inhibitor p21 (p21) plays a role in immune system processes like cell cycle, senescence, stem cell quiescence, and apoptosis.
  • Dysfunction of p21 may contribute to the development of systemic autoimmune diseases.

Purpose of the Study:

  • To investigate the role of p21 deficiency in T cell activation, proliferation, and autoimmune manifestations.
  • To determine if p21 deficiency alone can induce a lupus-like disease.

Main Methods:

  • Generation of mixed background p21-deficient 129/Sv x C57BL/6 mice.
  • Assessment of T cell cycling, activation, and proliferation in vitro and in vivo.
  • Analysis of autoantibodies, hypergammaglobulinemia, lymphoid organ size, and kidney pathology.
  • Evaluation of gender effects on autoimmune manifestations.

Main Results:

  • p21-deficient mice exhibited increased T cell cycling and activation.
  • Enhanced homeostatic proliferation of p21-deficient T cells was observed.
  • Moderate hypergammaglobulinemia and low-incidence anti-chromatin autoantibodies were detected.
  • Mild lymphoid organ enlargement and kidney pathology were noted, with no gender bias.

Conclusions:

  • p21 deficiency significantly enhances T cell activation and homeostatic proliferation.
  • p21 deficiency can induce mild autoimmune manifestations but does not cause a full lupus-like disease.
  • The role of p21 in autoimmunity warrants further investigation.

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