Streptococcus mutans wall-associated protein A promotes TLR4-induced dendritic cell maturation

Scand J Immunol. 2014 Aug;80(2):121-6. doi: 10.1111/sji.12194.

Abstract

Dendritic cells orchestrate innate and adaptive immune responses, which are central to establishing efficient responses to vaccination. Wall-associated protein A (WapA) of Streptococcus mutans was previously used as a vaccine in animal studies for immunization against dental caries. However, as a cell surface protein, whether WapA activates innate immune responses and the effects of WapA on DCs remain unclear. In this study, WapA was cloned into the GST fusion vector pEBG, which can be expressed efficiently in mammalian cells. We found that when added before stimulation with LPS, purified WapA-GST protein increased TLR4-induced NF-κB and MAPK signalling pathway activation. Pretreatment with WapA-GST also increased LPS-induced proinflammatory cytokine production by DCs, including IL-12, IL-6 and TNF-α. Furthermore, expression of the DC maturation markers CD80/86, CD40 and MHC II was also increased by WapA pretreatment. These data indicate that WapA is recognized by DCs and promotes DC maturation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Bacterial / genetics
  • Antigens, Bacterial / immunology*
  • B7-1 Antigen / biosynthesis
  • B7-2 Antigen / biosynthesis
  • Bacterial Proteins / genetics
  • Bacterial Proteins / immunology*
  • CD40 Antigens / biosynthesis
  • Cell Differentiation / immunology
  • Cells, Cultured
  • Dendritic Cells / immunology*
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Humans
  • I-kappa B Kinase / metabolism
  • Interleukin-12 / biosynthesis
  • Interleukin-6 / biosynthesis
  • JNK Mitogen-Activated Protein Kinases / metabolism
  • Lipopolysaccharides
  • MAP Kinase Signaling System / immunology
  • Membrane Proteins / genetics
  • Membrane Proteins / immunology
  • Membrane Proteins / pharmacology
  • Phosphorylation / drug effects
  • Streptococcus mutans / immunology*
  • Toll-Like Receptor 4 / immunology*
  • Transcription Factor RelA / metabolism
  • Tumor Necrosis Factor-alpha / biosynthesis
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • Antigens, Bacterial
  • B7-1 Antigen
  • B7-2 Antigen
  • Bacterial Proteins
  • CD40 Antigens
  • CD86 protein, human
  • IL6 protein, human
  • Interleukin-6
  • Lipopolysaccharides
  • Membrane Proteins
  • TLR4 protein, human
  • Toll-Like Receptor 4
  • Transcription Factor RelA
  • Tumor Necrosis Factor-alpha
  • wapA protein, Bacillus subtilis
  • Interleukin-12
  • CHUK protein, human
  • I-kappa B Kinase
  • IKBKB protein, human
  • Extracellular Signal-Regulated MAP Kinases
  • JNK Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases