Protein kinase Cepsilon is dispensable for TCR/CD3-signaling

Mol Immunol. 2005 Feb;42(3):305-10. doi: 10.1016/j.molimm.2004.07.007.


PKCepsilon has been strongly linked to cell activation and proliferation in many cell types, including leukemic T-cell lines. In particularly, an essential role of PKCepsilon has been established in the IKK-beta/I-kappaB/NF-kappaB transactivation cascade. To study the physiological function of PKCepsilon in primary T-cells, we used our newly established PKCepsilon null mice. Unexpectedly, however, we did not reveal any defect in the development and function of CD3+ T-cells. Proliferative responses as well as IL-2 cytokine secretion of PKCepsilon-deficient T-cells induced by allogenic MHC, plate-bound anti-CD3 antibodies (with or without anti-CD28 costimulation), or mitogenic stimuli such as phorbol ester and Ca2+ ionophore were comparable with wild-type controls. Consistently, after CD3/CD28 engagement, deficiency of PKCepsilon did not impair NF-kappaB transactivation as well as CD25, CD44 and CD69 induction. Thus, PKCepsilon-deficient T-cells had similar physiological thresholds for activation in vitro. This finding suggests that PKCepsilon plays a redundant role in TCR-induced regulation of T-cell proliferation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD / biosynthesis
  • Antigens, CD / genetics
  • Electrophoretic Mobility Shift Assay
  • Interleukin-2 / biosynthesis
  • Interleukin-2 / genetics
  • Lymphocyte Activation / genetics
  • Lymphocyte Activation / physiology*
  • Mice
  • Mice, Mutant Strains
  • Mutation / genetics
  • NF-kappa B / physiology
  • Protein Kinase C / genetics
  • Protein Kinase C / physiology*
  • Protein Kinase C-epsilon
  • Receptor-CD3 Complex, Antigen, T-Cell / physiology*
  • T-Lymphocytes / enzymology*
  • T-Lymphocytes / immunology*
  • Transcriptional Activation / genetics


  • Antigens, CD
  • Interleukin-2
  • NF-kappa B
  • Receptor-CD3 Complex, Antigen, T-Cell
  • Prkce protein, mouse
  • Protein Kinase C
  • Protein Kinase C-epsilon