| Author | Gaspar-Elsas, M. I. | |
| Author | Queto, T. | |
| Author | Vasconcelos, Zilton Farias Meira de | |
| Author | Jones, C. P. | |
| Author | Lannes-Vieira, Joseli | |
| Author | Xavier-Elsas, P. | |
| Access date | 2017-08-29T14:47:07Z | |
| Available date | 2017-08-29T14:47:07Z | |
| Document date | 2009 | |
| Citation | GASPAR-ELSAS, M. I. et al. Evidence for a regulatory role of a4 – integrins in the maturation of eosinophils generated from the bone marrow in the presence of dexamethasone. Clinical & Experimental Allergy, v. 39, p. 1187-1198, Aug. 2009. | pt_BR |
| ISSN | 0954-7894 | pt_BR |
| URI | https://www.arca.fiocruz.br/handle/icict/20810 | |
| Language | eng | pt_BR |
| Publisher | Wiley | pt_BR |
| Rights | restricted access | |
| Subject in Portuguese | Medula Óssea | pt_BR |
| Subject in Portuguese | Eosinófilos | pt_BR |
| Subject in Portuguese | Glucocorticoides | pt_BR |
| Subject in Portuguese | Prostaglandina | pt_BR |
| Subject in Portuguese | Moléculas de adesão | pt_BR |
| Title | Evidence for a regulatory role of alpha 4-integrins in the maturation of eosinophils generated from the bone marrow in the presence of dexamethasone | pt_BR |
| Type | Article | |
| DOI | 10.1111/j.1365-2222.2009.03289.x | |
| Abstract | Background: Although eosinophils co-express multiple integrin receptors, the contributions of integrins to eosinophil development have not been explored. We previously described extensive aggregation and cytological immaturity in eosinophils developing in bone-marrow (BM) cultures exposed to dexamethasone. Here we examined the relationship of alpha 4 integrins with these effects of dexamethasone. Objectives: We evaluated: (a) the effects of exposure to dexamethasone in BM culture on eosinophil expression of alpha 4 integrin receptors and ligands; (b) the contribution of alpha 4 integrins to eosinophil aggregation and maturation. Methods: Cultures were established with IL-5 (alone or with dexamethasone) for up to 7 days, and eosinophil production, alpha 4 integrin receptor/ligand expression, aggregation and morphology were evaluated before and after targeting alpha 4 integrin-dependent adhesions. Because prostaglandin E2 (PGE2) modifies the effects of dexamethasone on eosinophilopoiesis, PGE2 effects on alpha 4 integrin expression and function were also evaluated. Results: Dexamethasone increased the yield of eosinophils up to day 7. The frequency of eosinophils expressing alpha 4, beta1 and beta 7 integrin receptors at day 7 was also increased by dexamethasone. Eosinophils also expressed the alpha 4 beta 1 ligand, VCAM-1. Dexamethasone increased the expression of alpha 4 integrin and VCAM-1 in aggregates containing eosinophils as early as day 3. PGE2, added up to day 3, modified the effects of dexamethasone to suppress the expression of alpha 4 integrin, decrease aggregation and promote cytological maturation of eosinophils recovered at day 7. Dissociation of immature eosinophils from clusters present at day 3 by reagents targeting alpha 4 or beta1 integrins or VCAM-1 also induced cytological maturation. The concordant effects of targeting alpha 4 integrins with drugs and antibodies support a relationship between alpha 4-mediated aggregation and maturational arrest. Conclusions: These observations support a novel role for alpha 4 integrin receptors and ligands in eosinophilopoiesis. In addition, increased alpha 4 expression following glucocorticoid exposure may contribute to the retention and accumulation of eosinophils in haemopoietic tissue. | pt_BR |
| Affilliation | Fundação Oswaldo Cruz. Instituto Fernandes Figueira. Departamento de Pediatria. Rio de Janeiro, RJ, Brasil. | pt_BR |
| Affilliation | Fundação Oswaldo Cruz. Instituto Fernandes Figueira. Departamento de Pediatria. Rio de Janeiro, RJ, Brasil. | pt_BR |
| Affilliation | Fundação Oswaldo Cruz. Instituto Fernandes Figueira. Departamento de Pediatria. Rio de Janeiro, RJ, Brasil. | pt_BR |
| Affilliation | Universidade Federal do Rio de Janeiro. Instituto de Microbiologia Prof. Paulo de Góes. Departamento de Imunologia. Rio de Janeiro, RJ, Brasil. | pt_BR |
| Affilliation | Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia das Interações. Rio de Janeiro, RJ, Brasil. | pt_BR |
| Affilliation | Universidade Federal do Rio de Janeiro. Instituto de Microbiologia Prof. Paulo de Góes. Departamento de Imunologia. Rio de Janeiro, RJ, Brasil. | pt_BR |
| Subject | Adhesion molecules | pt_BR |
| Subject | Bone marrow | pt_BR |
| Subject | Eosinophils | pt_BR |
| Subject | Glucocorticoids | pt_BR |
| Subject | Prostaglandin | pt_BR |
| e-ISSN | 1365-2222 | |
| Embargo date | 2030-12-31 | |
