G-CSF suppresses allergic pulmonary inflammation, downmodulating cytokine, chemokine and eosinophil production Túlio Queto a , Zilton F.M. Vasconcelos a , Ricardo Alves Luz a,b , Carina Anselmo a , Ana Amélia A. Guiné b , Patricia Machado R. e Silva c , Júlia Farache d , José Marcos T. Cunha e , Adriana C. Bonomo b,d , Maria Ignez C. Gaspar-Elsas a , Pedro Xavier-Elsas b, ⁎ a Dept. of Pediatrics, Instituto Fernandes Figueira, FIOCRUZ, Rio de Janeiro, Brazil b Dept. of Immunology, Instituto de Microbiologia Professor Paulo de Góes, UFRJ, Rio de Janeiro, Brazil c Laboratory of Inflammation, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil d Division of Experimental Medicine, INCa, Rio de Janeiro, Brazil e Faculdade de Medicina, UFRJ, Rio de Janeiro, RJ, Brazil abstract article info Article history: Received 17 September 2010 Accepted 2 March 2011 Keywords: Cytokines Eosinophils Granulocyte Colony-Stimulating Factor Th1–Th2 balance Experimental therapies Aims: Granulocyte Colony-Stimulating Factor (G-CSF), which mobilizes hemopoietic stem cells (HSC), is believed to protect HSC graft recipients from graft-versus-host disease by enhancing Th2 cytokine secretion. Accordingly, G-CSF should aggravate Th2-dependent allergic pulmonary inflammation and the associated eosinophilia. We evaluated the effects of G-CSF in a model of allergic pulmonary inflammation. Main methods: Allergic pulmonary inflammation was induced by repeated aerosol allergen challenge in ovalbumin-sensitized C57BL/6J mice. The effects of allergen challenge and of G-CSF pretreatment were evaluated by monitoring: a) eosinophilia and cytokine/chemokine content of bronchoalveolar lavage fluid, pulmonary interstitium, and blood; b) changes in airway resistance; and c) changes in bone-marrow eosinophil production. Key findings: Contrary to expectations, G-CSF pretreatment neither induced nor enhanced allergic pulmonary inflammation. Instead, G-CSF: a) suppressed accumulation of infiltrating eosinophils in bronchoalveolar, peribronchial and perivascular spaces of challenged lungs; and b) prevented ovalbumin challenge-induced rises in airway resistance. G-CSF had multiple regulatory effects on cytokine and chemokine production: in bronchoalveolar lavage fluid, levels of IL-1 and IL-12 (p40), eotaxin and MIP-1a were decreased; in plasma, KC, a neutrophil chemoattractant, was increased, while IL-5 was decreased and eotaxin was unaffected. In bone-marrow, G-CSF: a) prevented the increase in bone-marrow eosinophil production induced by ovalbumin challenge of sensitized mice; and b) selectively stimulated neutrophil colony formation. Significance: These observations challenge the view that G-CSF deviates cytokine production towards a Th2 profile in vivo, and suggest that this neutrophil-selective hemopoietin affects eosinophilic inflammation by a combination of effects on lung cytokine production and bone-marrow hemopoiesis. © 2011 Elsevier Inc. All rights reserved. Introduction Granulocyte Colony-Stimulating Factor (G-CSF) (Demetri and Griffin 1991) promotes expansion and maturation of neutrophil populations, further increasing their effector capacity and lifespan (Shochat et al. 2007). G-CSF mobilizes hemopoietic stem cells (HSC) to peripheral blood, which is increasingly used as a source of HSC for transplantation (Pusic and DiPersio 2008; Nervi et al. 2006). G-CSF has numerous additional immunoregulatory effects (Rutella et al. 2005; Xiao et al. 2007). Unexpectedly, G-CSF use in HSC mobilization decreases the incidence of severe acute graft-versus-host disease (GVHD), a major complication of HSC transplantation in both humans and mice (Bensinger et al. 2001; Berger et al. 1999; Ji et al. 2002). Because acute GVHD is mediated by Th1 lymphocytes (Ferrara 1998), and Th2 lymphocytes prevent the disease (Fowler et al. 1994), it has been suggested that G-CSF promotes Th2 responses (Pan et al. 1995), an effect believed to underlie its beneficial effects in other autoimmune and inflammatory diseases (Hadaya et al. 2005; Hommes et al. 1996; Zavala et al. 2002). However, G-CSF suppresses production of both Th1 and Th2 cytokines by activating neutrophil granulocytes (Vasconcelos et al. 2003), which possibly accounts for its protective activity against GVHD in humans and mice (Vasconcelos et al. 2006). This prompted us to reexamine the assumption that G-CSF acts in vivo to promote Th2- mediated responses, using a murine model for allergic pulmonary inflammation. This model is highly dependent on Th2 lymphocytes, Life Sciences 88 (2011) 830–838 ⁎ Corresponding author at: Dept. Immunology, Instituto de Microbiologia Prof. Paulo de Góes, UFRJ, CCS Bloco I room I-2-066, Rio de Janeiro, 21941–590, Brazil. Tel./fax: +55 21 25541731. E-mail address: pxelsas@yahoo.com.br (P. Xavier-Elsas). 0024-3205/$ – see front matter © 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.lfs.2011.03.001 Contents lists available at ScienceDirect Life Sciences journal homepage: www.elsevier.com/locate/lifescie