Receptor reserve analysis of the human CCR3 receptor in eosinophils and CCR3-transfected cells.
J Leukoc Biol
; 67(3): 441-7, 2000 Mar.
Article
em En
| MEDLINE
| ID: mdl-10733106
ABSTRACT
A novel pharmacological study of CCR3 receptor reserve in a CCR3-transfected cell (CREM3) and human eosinophils was done; functional responses measured were increases in intracellular calcium and chemotaxis. Eotaxin, eotaxin-2, monocyte chemoattractant protein-4 (MCP-4), RANTES, and MCP-3 induced similar maximal eosinophil chemotaxis, whereas MCP-3 and RANTES induced submaximal calcium responses in eosinophils compared to eotaxin, MCP-4, and eotaxin-2. This suggested a receptor reserve in the chemotaxis response. Receptor reserve was quantitated for eotaxin. Occupancy of all CCR3 receptors was required for a maximal calcium response in both CREM3 and eosinophils (reserve = 1.0 or 0.17, respectively); the stimulus-calcium response relationship was linear, indicating no receptor reserve. In contrast, in eosinophils a large receptor reserve (6.5) was found for chemotaxis, where occupancy of 15% receptors drove half-maximal responses. These studies indicate that CCR3 interacts with G-proteins that are poorly coupled to the calcium response, whereas coupling efficiency and/or amplification to the chemotaxis apparatus in human eosinophils is significantly greater.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Receptores de Quimiocinas
/
Quimiocinas CC
/
Eosinófilos
Limite:
Animals
/
Humans
Idioma:
En
Revista:
J Leukoc Biol
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Estados Unidos