2005 Fiscal Year Final Research Report Summary
Study of the effect of environmental chemicals on the high-affinity IgG receptor-mediated signal transudation of mest cells.
| Project/Area Number |
15590120
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Environmental pharmacy
|
|---|
| Research Institution | National Intsitute of Health Sciences |
|---|
Principal Investigator |
TESHIMA Reiko National Institute of Health Sciences, Division of Biochemistry and Immunochemistory, Section Chief, 機能生化学部, 研究員 (50132882)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Ryosuke National Institute of Health Sciences, Division of Biochemistry and Immunochemistry, Senior Scientist, 機能生化学部, 主任研究官 (50333357)
|
|---|
| Project Period (FY) |
2003 – 2005
|
| Keywords | Canine Mast cells / High-affinity IgG receptor / Degranulation / cDNA / Canine IgG / Substance P / Environmental chemicals |
|---|
| Research Abstract |
1.Canine cutaneous mastocytoma-derived (CM-MC) cells were activated both IgG- and IgE-mediated mechanisms. IgG-mediated protein tyrosine phosphorylation and Ca^<2+> influx were similar to those mediated by IgE. Protein kinase inhibitor staurosporine inhibited IgG-mediated [Ca^<2+>]i elevation and histamine release in a dose-dependent manner.
2.The presence of high affinity IgG receptors (FcγRI) protein and mRNA in CM-MC cells was determined by immunoprecipitation and RT-PCR methods. Then, the cDNA sequence of FcγRIα subunit was identified. The entire canine FcγRIα cDNA was 1119bp long (GenBank accession number, AB 101519). The overall identity of the canine FcγRIa cDNA to its human and mouse counterparts was 84% and 78%, respectively.
3.We transfected cDNA of FcγRIα to COS-7 cells to examine the binding of monomeric IgG to the cells. The cDNA of canine FcγRIα was cloned by RT-PCR and 5'/3'-RACE from total RNA of CM-MC cells. The cDNA was ligated to mammalian expression vector and transfected into COS -7 cells. The binding of IgG onto the COS -7 cells was detected by flow-cytometry.
4.CM-MC was activated by Substance P (10-30 μM) and C5a (0.5-1μM) dose-dependently. [Ca^<2+>]i elevation and degranulation by these substances was inhibited by islet- activated protein (IAP). Therefore, the activation of these substances seemed to be dependent on G-protein-coupled mechanism
5.In conclusion, CM-MC cells were useful for the study of allergic inflammation caused by IgG-dependent mechanisms. The environmental chemicals that affect Substance P and C5a production might influence allergic inflammation caused by IgG-dependent mast cell activation.
|
Research Products
(12 results)
