Related Experiment Video
Updated: Aug 7, 2026
Isolation Protocol of Mouse Monocyte-derived Dendritic Cells and Their Subsequent In Vitro Activation with Tumor Immune Complexes
Published on: May 31, 2018
Monocyte chemoattractant protein (MCP)-1 production via functionally reconstituted Fcalpha receptor (CD89) on
T Tsuge1, Y Suzuki, T Shimokawa
1Department of Internal Medicine, Juntendo University School of Medicine, 2-1-1 Hongo, 113-8421 Tokyo, Japan, Bunkyo-ku.
Insights
Fc alpha receptor (FcalphaR) and FcRgamma chain reconstitution in mesangial cells mediates IgA-induced MCP-1 production. This suggests FcalphaR activation in mesangial cells contributes to IgA nephropathy pathogenesis.
Area of Science:
- Immunology
- Nephrology
- Cell Biology
Background:
- Fc alpha receptor (FcalphaR; CD89) binds IgA, mediating immune responses.
- FcalphaR's role in mesangial cells is crucial for IgA nephropathy pathogenesis but remains debated.
- Monocyte chemoattractant protein-1 (MCP-1) production by mesangial cells contributes to glomerular injury.
Purpose of the Study:
- To investigate the biological functions of FcalphaR in mesangial cells.
- To establish mesangial transfectants expressing FcalphaR with or without the FcRgamma chain.
- To assess MCP-1 production in response to aggregated IgA.
Main Methods:
- Transfection of murine mesangial cell lines with human FcalphaR and FcRgamma chain cDNA.
- Examination of protein tyrosine phosphorylation via immunoprecipitation after FcalphaR cross-linking.
- Quantification of MCP-1 production using sandwich ELISA upon stimulation with aggregated IgA.
Main Results:
- Stable expression of FcalphaR with or without FcRgamma chain achieved in mesangial transfectants.
- FcRgamma chain and syk kinase phosphorylation detected in FcalphaR-expressing cells.
- Aggregated IgA significantly increased MCP-1 production in FcalphaR(+)/gamma(+) cells compared to FcalphaR(+) or untransfected cells.
Conclusions:
- FcalphaR and FcRgamma chain can be reconstituted in mesangial cells, mediating dose-dependent MCP-1 production stimulated by aggregated IgA.
- FcalphaR activation in mesangial cells occurs via intrinsic cellular machinery.
- Mechanisms of FcalphaR induction in mesangial cells require further investigation.
Background:
Fc alpha receptor (FcalphaR; CD89) is the receptor for Fc portion of IgA in various cells, and displays various immunological responses on binding. It is important to analyze the mesangial functions via FcalphaR in the pathogenesis of IgA nephropathy. However, it is still controversial whether FcalphaR is expressed on mesangial cells. To assess biological functions of FcalphaR on the mesangial cells, we established mesangial transfectants that expressed FcalphaR with or without FcRgamma chain that is a common signaling molecule of FcRs. The production of monocyte chemoattractant protein-1 (MCP-1) by mesangial cells is known to contribute to cellular infiltration into glomeruli and subsequent glomerular injuries.
Methods:
Murine mesangial cell lines (SV40 MES 13) were transfected with cDNA of the human FcalphaR. Furthermore, we co-transfected some of the FcalphaR transfectants with cDNA of human FcRgamma chain. The tyrosine phosphorylation of the intra-mesangial proteins after FcalphaR cross-linking was examined by immunoprecipitation. MCP-1 production from each transfectant stimulated with heat aggregated IgA was determined by sandwich ELISA.
Results:
Two kinds of mesangial transfectants stably expressed human FcalphaR with or without FcRgamma chain (FcalphaR(+), FcalphaR(+)/gamma(+)). Phosphorylation of FcRgamma chain and syk kinase was detected in FcalphaR(+) and FcalphaR(+)/gamma(+) cells, but not in untransfected cells. Aggregated IgA induced significantly higher MCP-1 production in FcalphaR(+)/gamma(+) than those in FcalphaR(+) or untransfected control.
Conclusions:
Present study demonstrated that FcalphaR and FcRgamma chain could be reconstituted in mesangial cells and mediated MCP-1 production by aggregated IgA in a dose-dependent manner. Current data would argue that FcalphaR can be activated in mesangial cells through their own machinery, although underlying mechanisms for FcalphaR induction in mesangial cells remain unclear.
