Dexamethasone and allergenic sensitization upregulate expression of A4 integrins in eosinophil precursors (2005)
- Authors:
- Autor USP: VARGAFTIG, BERNARDO BORIS JORGE - ICB
- Unidade: ICB
- Assunto: FARMACOLOGIA
- Language: Português
- Abstract: Objetivo: A4 integrins are expressed on multipotent hemopoietic progenitors and play a role in their migration, homing, and proliferation. Systemic treatment with dexamethasone (Dex), in murine models of allergic inflammation, blocks eosinophil (EOS) recruitment to inflammatory sites. By contrast, Dex significantly increases eosinophil precursor responses to IL-5 in bone-marrow cultures. Eosinophils generated in the presence of IL-5 and Dex are highly aggregated and morphologically immature, suggesting that increased expression of adhesion molecules is accompanied by a maturational arrest. To evaluate the effect of Dex and allergenic sensitization on the expression of a4, b1 and b7 integrins during eosinopoiesis, and to correlate integrin expression with aggregation and morphological maturation. Métodos e Resultados: We evaluated the expression of a4 integrins (b1 and b7) in bone-marrow liquid cultures from naive, from ovalbumin-sensitized or from Dex-treated BALB/c mice, established in the presence of IL-5 (1ng.ml-1), alone or in association with Dex (10-7M). Integrin expression was evaluated at day 7 of culture by immunocytochemistry and by flow cytometry. Dex (10-7M) significantly increased the frequency of a4+ cells, as well as the intensity of expression of a4 in eosinophil precursors, relative to IL-5 control cultures (P< 0,001).) Dex significantly increased the frequency of b1+ eosinophils (P< 0,001), but not the frequency of b1+ mononuclearcells. In Dex-treated cultures, a4 integrin expression was highest in the region of contact between neighboring cells in aggregates. Neutralizing anti-a4 antibody, when added at day 3 of culture, was able to dissociate the clusters of aggregated immature eosinophils and made it possible for them to undergo terminal differentiation. By contrast, addition of anti-a4 antibody, at day 1 of culture, blocked eosinophilic differentiation induced by IL-5 (alone or in association with Dex). Ovalbumin sensitization and challenge increased a4 expression in bone-marrow cultures, but no maturational arrested was seen. Conclusões: Both Dex and allergic sensitization enhance a4 integrin expression in developing EOS. a4 integrins play a dual role in EOS differentiation.
- Imprenta:
- Publisher: Federação de Sociedades de Biologia Experimental
- Publisher place: Águas de Lindóia, São Paulo
- Date published: 2005
- Source:
- Título: Resumos
- Conference titles: Reunião Anual da Federação de Sociedades de Biologia Experimental, FeSBE
-
ABNT
GASPAR ELSAS, M. I. et al. Dexamethasone and allergenic sensitization upregulate expression of A4 integrins in eosinophil precursors. 2005, Anais.. Águas de Lindóia, São Paulo: Federação de Sociedades de Biologia Experimental, 2005. . Acesso em: 26 jan. 2026. -
APA
Gaspar Elsas, M. I., Vieira, J. L., Sales, S. C. M., Silva, C. P. J., Maximiano, E. S., Rodrigues, M. P. A., et al. (2005). Dexamethasone and allergenic sensitization upregulate expression of A4 integrins in eosinophil precursors. In Resumos. Águas de Lindóia, São Paulo: Federação de Sociedades de Biologia Experimental. -
NLM
Gaspar Elsas MI, Vieira JL, Sales SCM, Silva CPJ, Maximiano ES, Rodrigues MPA, Aragão LS, Masid D, Vargaftig BBJ, Elsas PPX. Dexamethasone and allergenic sensitization upregulate expression of A4 integrins in eosinophil precursors. Resumos. 2005 ;[citado 2026 jan. 26 ] -
Vancouver
Gaspar Elsas MI, Vieira JL, Sales SCM, Silva CPJ, Maximiano ES, Rodrigues MPA, Aragão LS, Masid D, Vargaftig BBJ, Elsas PPX. Dexamethasone and allergenic sensitization upregulate expression of A4 integrins in eosinophil precursors. Resumos. 2005 ;[citado 2026 jan. 26 ] - Dendritic cells recruited to the lungs shortly after intranasal delivery of Mycobacterium bovis BCG drive the primary immune response towards a TH1-type cytokine production
- Ectopic lung transplantation induces the accumulation of eosinophil progenitors in the recipients' lungs through an allergen- and interleukin-5-dependent mechanism
- A MARCKS-related peptide blocks mucus hypersecretion in a mouse model of asthma
- Ectopic grafts of allergic lung tissue induce accumulation of hemopoietic cells in the graft recipient's own lungs by releasing il-5
- Nitric oxide and FasL are required for eosinophil apoptosis induction by Prostaglandin E2
- Allergic lung grafts induce acumulation of hemopoietic cells in lungs and increase the response of bone-marrow cells to IL-5 in a ectopic transplantation model
- Novos alvos para medicamentos contra a asma: o exemplo do BCG e de um de seus derivados, o "Extended freez dried" BCG
- Effect of allergen sensitization on eosinophil precursor responses to cytokines and chemokines in bone-marrow culture
- Effect of allergen sensitization on eosinophil precursor responses to cytokines and chemokines in bone-marrow culture
- Novel mechanisms of the control of the allergic reaction-immune regulation as a target
How to cite
A citação é gerada automaticamente e pode não estar totalmente de acordo com as normas
