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Mediators of Inflammation
Volume 2014 (2014), Article ID 102160, 13 pages
http://dx.doi.org/10.1155/2014/102160
Research Article

5-Lipoxygenase-Dependent Recruitment of Neutrophils and Macrophages by Eotaxin-Stimulated Murine Eosinophils

1Department of Immunology, IMPG, Universidade Federal do Rio de Janeiro, CCS, Bloco I, Room I-2-066, 21941-590 Rio de Janeiro, Brazil
2Department of Pediatrics, IFF, FIOCRUZ, 22250-020 Rio de Janeiro, Brazil
3Department of Medical Microbiology, IMPG, Universidade Federal do Rio de Janeiro, 21941-590 Rio de Janeiro, Brazil

Received 14 November 2013; Revised 14 January 2014; Accepted 15 January 2014; Published 25 February 2014

Academic Editor: Shaoheng He

Copyright © 2014 Ricardo Alves Luz et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The roles of eosinophils in antimicrobial defense remain incompletely understood. In ovalbumin-sensitized mice, eosinophils are selectively recruited to the peritoneal cavity by antigen, eotaxin, or leukotriene(LT)B4, a 5-lipoxygenase (5-LO) metabolite. 5-LO blockade prevents responses to both antigen and eotaxin. We examined responses to eotaxin in the absence of sensitization and their dependence on 5-LO. BALB/c or PAS mice and their mutants (5-LO-deficient ALOX; eosinophil-deficient GATA-1) were injected i.p. with eotaxin, eosinophils, or both, and leukocyte accumulation was quantified up to 24 h. Significant recruitment of eosinophils by eotaxin in BALB/c, up to 24 h, was accompanied by much larger numbers of recruited neutrophils and monocytes/macrophages. These effects were abolished by eotaxin neutralization and 5-LO-activating protein inhibitor MK886. In ALOX (but not PAS) mice, eotaxin recruitment was abolished for eosinophils and halved for neutrophils. In GATA-1 mutants, eotaxin recruited neither neutrophils nor macrophages. Transfer of eosinophils cultured from bone-marrow of BALB/c donors, or from ALOX donors, into GATA-1 mutant recipients, i.p., restored eotaxin recruitment of neutrophils and showed that the critical step dependent on 5-LO is the initial recruitment of eosinophils by eotaxin, not the secondary neutrophil accumulation. Eosinophil-dependent recruitment of neutrophils in naive BALB/c mice was associated with increased binding of bacteria.