Involvement of protein kinase C in C5a-primed neutrophils for ANCA-mediated activation

Mol Immunol. 2013 May;54(1):68-73. doi: 10.1016/j.molimm.2012.10.041. Epub 2012 Nov 28.


C5a and the neutrophil C5a receptor play a central role in antineutrophil cytoplasmic antibody (ANCA)-mediated neutrophil recruitment and activation. Our recent study found that activation of p38 mitogen-activated protein kinase (p38MAPK), extracellular signal-regulated kinase (ERK) and phosphoinositol 3-kinase (PI3K) are all important steps in the translocation of ANCA antigens by C5a-mediated priming and activation of neutrophils. The current study further investigated the protein kinase C (PKC) pathway of C5a-mediated neutrophils for ANCA-induced activation. The effect of the PKC inhibitor (bisindolylmaleimide I, BIS) was tested on respiratory burst and degranulation of C5a-primed neutrophils activated with ANCA, as well as on C5a-induced increase in expression of PR3 and MPO. For C5a-primed neutrophils for MPO-ANCA-induced respiratory burst, the mean fluorescence intensity (MFI) value was 369.8±18.8, which decreased to 308.3±14.2 upon pre-incubation with BIS (P<0.001). For PR3-ANCA-positive IgG, the MFI value increased in C5a-primed neutrophils, which decreased upon pre-incubation with BIS. The lactoferrin concentration increased from 414.8±26.9 ng/ml in the non-primed neutrophils supernatant to 1099.8±80.7 ng/ml in C5a-primed neutrophils induced by MPO-ANCA-positive IgG supernatant (P<0.001), and decreased to 814.5±45.3 ng/ml upon pre-incubation with BIS (P<0.01). The lactoferrin concentration also increased in C5a-primed neutrophils induced by PR3-ANCA-positive IgG supernatant and decreased upon pre-incubation with BIS. Membrane expression of PR3 (mPR3) expression increased from 788.0±87.5 in untreated cells to 1071.3±81.3 after C5a treatment and decreased to 827.3±48.1 by BIS (P<0.05). Activation of PKC is an important step in the translocation of ANCA antigens and C5a-induced activation of neutrophils by ANCA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Antineutrophil Cytoplasmic / immunology
  • Antibodies, Antineutrophil Cytoplasmic / metabolism
  • Antibodies, Antineutrophil Cytoplasmic / pharmacology*
  • Cell Degranulation / drug effects
  • Cell Degranulation / immunology
  • Cell Respiration / drug effects
  • Cells, Cultured
  • Complement C5a / agonists
  • Complement C5a / immunology
  • Complement C5a / metabolism*
  • Humans
  • Lymphocyte Activation / drug effects*
  • Lymphocyte Activation / immunology
  • Myeloblastin / antagonists & inhibitors
  • Myeloblastin / immunology
  • Myeloblastin / metabolism
  • Neutrophils / immunology*
  • Neutrophils / metabolism
  • Neutrophils / physiology
  • Peroxidase / antagonists & inhibitors
  • Peroxidase / immunology
  • Peroxidase / metabolism
  • Phosphorylation
  • Protein Kinase C / antagonists & inhibitors
  • Protein Kinase C / metabolism
  • Protein Kinase C / physiology*
  • Protein Kinase Inhibitors / pharmacology
  • Protein Transport / drug effects
  • Protein Transport / immunology


  • Antibodies, Antineutrophil Cytoplasmic
  • Protein Kinase Inhibitors
  • Complement C5a
  • Peroxidase
  • Protein Kinase C
  • Myeloblastin