NF-kappaB induction by bisperoxovanadium compounds requires CD45, p36(LAT), PKC, and IKK activity and exhibits kinetics of activation comparable to those of TCR/CD28 coengagement

Biochemistry. 2003 Jul 15;42(27):8260-71. doi: 10.1021/bi034013b.

Abstract

We have previously shown that bisperoxovanadium (bpV) phosphotyrosyl phosphatase inhibitors can potently activate NF-kappaB. We have already determined that p56(lck), ZAP-70, SLP-76, capacitative entry of calcium, and calcium-regulated effectors are important in bpV-induced NF-kappaB activation. In this study, we evaluated whether other signal transducers previously reported in NF-kappaB induction by T cell activating stimuli are also activated by bpV compounds. Nuclear translocation of NF-kappaB was evaluated in cell lines deficient for either CD45 or p36(LAT) to assess the role of these signal transducers in bpV-mediated NF-kappaB activation. A deficiency of either protein greatly reduced the extent of NF-kappaB nuclear translocation following bpV treatment. Isoform-specific PKC inhibitors were then used to show that bpV compounds activate NF-kappaB through both calcium-sensitive and -insensitive PKC isoforms. The implication of the IkappaB-kinase complex was then investigated through the use of an IkappaBalpha-specific kinase assay and plasmids expressing catalytically inactive forms of IKKalpha and IKKbeta. Upstream kinases involved in IKK complex activation such as TPL-2/COT, NIK, and IKKepsilon were also shown to play an important role in bpV-mediated NF-kappaB activation. Finally, reporter gene transcriptional assays and gel shift assays were performed to compare the kinetics of activation of NF-kappaB by bpV with those of antigenic and TNFalpha stimulation. We demonstrate, both in Jurkat cells and in primary T cells, that bpV-mediated NF-kappaB activation kinetics are comparable to those of an antigenic stimulation but occur much slower than the kinetics seen upon TNFalpha treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • CD28 Antigens / metabolism*
  • Cell Line
  • Enzyme Activation
  • Humans
  • Kinetics
  • Leukocyte Common Antigens / metabolism*
  • NF-kappa B / biosynthesis*
  • Phosphorylation
  • Protein Kinase C / metabolism*
  • Receptors, Antigen, T-Cell / metabolism*
  • Tyrosine / metabolism
  • Vanadium Compounds / pharmacology*

Substances

  • CD28 Antigens
  • NF-kappa B
  • Receptors, Antigen, T-Cell
  • Vanadium Compounds
  • bisperoxovanadium
  • Tyrosine
  • Protein Kinase C
  • Leukocyte Common Antigens