Platelet-activating factor drives eotaxin production in an allergic pleurisy in mice.
1. The activation of eosinophils via G-protein-coupled seven transmembrane receptors play a necessary role in the recruitment of these cells into tissue. The present study investigates a role for PAF in driving eotaxin production and eosinophil recruitment in an allergic pleurisy model in mice. 2. The intrapleural injection of increasing doses of PAF (10(-11) to 10(-9) moles per cavity) induced a dose- and PAF receptor-dependent recruitment of eosinophils 48 h after stimulation. 3. Intrapleural injection of PAF induced the rapid (within 1 h) release of eotaxin into the pleural cavity of mice and an anti-eotaxin antibody effectively inhibited PAF-induced recruitment of eosinophils. 4. Eosinophil recruitment in the allergic pleurisy was markedly inhibited by the PAF receptor antagonist UK-74,505 (modipafant, 1 mg kg(-1)). Moreover, recruitment of eosinophils in sensitized and challenged PAF receptor-deficient animals was lower than that observed in wild-type animals. 5. Blockade of PAF receptors with UK-74,505 suppressed by 85% the release of eotaxin in the allergic pleurisy. 6. Finally, the injection of a sub-threshold dose of PAF and eotaxin cooperated to induce eosinophil recruitment in vivo. 7. In conclusion, the production of PAF in an allergic reaction could function in multiple ways to facilitate the recruitment of eosinophils -- by facilitating eotaxin release and by cooperating with eotaxin to induce greater recruitment of eosinophils.
Klein
André
A
Immunopharmacology, Departamento de Bioquímica e Imunologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Pinho
Vanessa
V
Alessandrini
Ana Letícia
AL
Shimizu
Takao
T
Ishii
Satoshi
S
Teixeira
Mauro M
MM
D000818:Animals; D054413:Chemokine CCL11; D019742:Chemokines, CC / Q000096:biosynthesis* / Q000276:immunology; D002634:Chemotaxis, Leukocyte / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004804:Eosinophils / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology; D010972:Platelet Activating Factor / Q000276:immunology / Q000494:pharmacology / Q000502:physiology*; D010980:Platelet Membrane Glycoproteins / Q000037:antagonists & inhibitors; D010994:Pleura / Q000276:immunology; D010998:Pleurisy / Q000276:immunology* / Q000503:physiopathology; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled
C515457:Ccl11 protein, mouse; D054413:Chemokine CCL11; D019742:Chemokines, CC; D010972:Platelet Activating Factor; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; C039351:platelet activating factor receptor; D010047:Ovalbumin