KOPS - Das Institutionelle Repositorium der Universität Konstanz

Expression of high- and low-affinity receptors for C3a on the human mast cell line, HMC-1

Expression of high- and low-affinity receptors for C3a on the human mast cell line, HMC-1

Zitieren

Dateien zu dieser Ressource

Dateien Größe Format Anzeige

Zu diesem Dokument gibt es keine Dateien.

LEGLER, Daniel F., Marcel LOETSCHER, Simon A. JONES, Clemens A. DAHINDEN, Michel AROCK, Bernhard MOSER, 1996. Expression of high- and low-affinity receptors for C3a on the human mast cell line, HMC-1. In: European Journal of Immunology. 26(4), pp. 753-758. ISSN 0014-2980. eISSN 1521-4141

@article{Legler1996-04Expre-37200, title={Expression of high- and low-affinity receptors for C3a on the human mast cell line, HMC-1}, year={1996}, doi={10.1002/eji.1830260405}, number={4}, volume={26}, issn={0014-2980}, journal={European Journal of Immunology}, pages={753--758}, author={Legler, Daniel F. and Loetscher, Marcel and Jones, Simon A. and Dahinden, Clemens A. and Arock, Michel and Moser, Bernhard} }

Moser, Bernhard Legler, Daniel F. Legler, Daniel F. Dahinden, Clemens A. Loetscher, Marcel Jones, Simon A. Loetscher, Marcel eng Jones, Simon A. 2017-02-08T07:43:11Z Moser, Bernhard Expression of high- and low-affinity receptors for C3a on the human mast cell line, HMC-1 The proteolytic cleavage product of complement component 3, (C3a), is like C4a and C5a, is a potent anaphylatoxin and induces the production of inflammatory mediators in phagocytes. Notably, mast cells respond to C3a with the release of vasoactive substances, including histamine. We have examined the function and receptor binding of C3a in a human leukemic mast cell line, HMC-1. Similar to chemoattractant agonists in leukocytes, C3a induced rapid cytosolic free calcium concentration increases in HMC-1 cells. EGTA did not diminish this response, indicating that mobilizable Ca<sup>2+</sup> was from intracellular stores. Receptors of C3a in HMC-1 cells couple in part to Bordetella pertussis toxin-sensitive G-proteins and, therefore, appear to belong to the family of serpentine receptors that require G-proteins for signal transduction. HMC-1 cells express two types of C3a receptors, C3aR1 and C3aR2, that were shown to bind <sup>125</sup>I-C3a with high-(K<sub>d</sub>1 = 2.1-4.8 nM) or low-affinity (K<sub>d</sub>2 = 30-150 nM), and both receptors are expressed at high level: 3 x 10<sup>5</sup>-6 x 10<sup>5</sup> C3aR1/cell and 5 x 10<sup>5</sup>-2.3 x 10<sup>6</sup> C3aR2/cell. Results from cross-linking experiments with <sup>125</sup>I-C3a fully agree with the presence of two different classes of C3a receptors in HMC-1 cells. Two membrane proteins with apparent molecular masses of 54-61 kDa (p57) and 86-107 kDa (p97) could be covalently modified with <sup>125</sup>I-C3a, and this cross-linking was inhibited with an excess of unlabeled C3a. Many of the known agonists for leukocytes including 13 chemokines (IL-8, NAP-2, GRO alpha, ENA-78, IP10, PF4, MCP-1, 2 and 3, RANTES, MIP-1 alpha, MIP-1 beta and I309), three neuropeptides (neuropeptide Y, somatostatin and calcitonin), as well as C5a, did not activate HMC-1 cells, indicating that C3a is one of a few protein ligands for which this cell line expresses specific receptors. The apparent selectivity for C3a and the abundant expression of C3a receptors make the HMC-1 cell line an excellent choice for the cloning of the receptor genes. 1996-04 Arock, Michel 2017-02-08T07:43:11Z Arock, Michel Dahinden, Clemens A.

Das Dokument erscheint in:

KOPS Suche


Stöbern

Mein Benutzerkonto