Entity

Time filter

Source Type


Charmoy M.,University of Lausannne | Brunner-Agten S.,University of Lausannne | Aebischer D.,University of Lausannne | Auderset F.,University of Lausannne | And 4 more authors.
PLoS Pathogens | Year: 2010

Neutrophils are rapidly and massively recruited to sites of microbial infection, where they can influence the recruitment of dendritic cells. Here, we have analyzed the role of neutrophil released chemokines in the early recruitment of dendritic cells (DCs) in an experimental model of Leishmania major infection. We show in vitro, as well as during infection, that the parasite induced the expression of CCL3 selectively in neutrophils from L. major resistant mice. Neutrophil-secreted CCL3 was critical in chemotaxis of immature DCs, an effect lost upon CCL3 neutralisation. Depletion of neutrophils prior to infection, as well as pharmacological or genetic inhibition of CCL3, resulted in a significant decrease in DC recruitment at the site of parasite inoculation. Decreased DC recruitment in CCL3-/- mice was corrected by the transfer of wild type neutrophils at the time of infection. The early release of CCL3 by neutrophils was further shown to have a transient impact on the development of a protective immune response. Altogether, we identified a novel role for neutrophil-secreted CCL3 in the first wave of DC recruitment to the site of infection with L. major, suggesting that the selective release of neutrophil-secreted chemokines may regulate the development of immune response to pathogens. © 2010 Charmoy et al.


de Albuquerque Taddei S.R.,Federal University of Minas Gerais | Queiroz-Junior C.M.,Federal University of Minas Gerais | Moura A.P.,Federal University of Minas Gerais | Andrade I.,Pontifical Catholic University of Minas Gerais | And 4 more authors.
Bone | Year: 2013

Bone remodeling is affected by mechanical loading and inflammatory mediators, including chemokines. The chemokine (C-C motif) ligand 3 (CCL3) is involved in bone remodeling by binding to C-C chemokine receptors 1 and 5 (CCR1 and CCR5) expressed on osteoclasts and osteoblasts. Our group has previously demonstrated that CCR5 down-regulates mechanical loading-induced bone resorption. Thus, the present study aimed to investigate the role of CCR1 and CCL3 in bone remodeling induced by mechanical loading during orthodontic tooth movement in mice. Our results showed that bone remodeling was significantly decreased in CCL3-/- and CCR1-/- mice and in animals treated with Met-RANTES (an antagonist of CCR5 and CCR1). mRNA levels of receptor activator of nuclear factor kappa-B (RANK), its ligand RANKL, tumor necrosis factor alpha (TNF-α) and RANKL/osteoprotegerin (OPG) ratio were diminished in the periodontium of CCL3-/- mice and in the group treated with Met-RANTES. Met-RANTES treatment also reduced the levels of cathepsin K and metalloproteinase 13 (MMP13). The expression of the osteoblast markers runt-related transcription factor 2 (RUNX2) and periostin was decreased, while osteocalcin (OCN) was augmented in CCL3-/- and Met-RANTES-treated mice. Altogether, these findings show that CCR1 is pivotal for bone remodeling induced by mechanical loading during orthodontic tooth movement and these actions depend, at least in part, on CCL3. © 2012 Elsevier Inc.


Russo R.C.,Federal University of Minas Gerais | Alessandri A.L.,Federal University of Minas Gerais | Garcia C.C.,Federal University of Minas Gerais | Cordeiro B.F.,Federal University of Minas Gerais | And 4 more authors.
American Journal of Respiratory Cell and Molecular Biology | Year: 2011

CC chemokines play an important role in the pathogenesis of idiopathic pulmonary fibrosis. Few studies have evaluated the efficacy of therapeutically targeting CC chemokines and their receptors during interstitial lung diseases. In the present study, the therapeutic effects of Evasin-1, a tick-derived chemokine-binding protein that has high affinity for CCL3/microphage inflammatory protein (MIP)-1α, was investigated in a murine model of bleomycininduced lung fibrosis. CCL3/MIP-1α concentrations in lung homogenates increased significantly with time after bleomycin challenge, and this was accompanied by increased number of leukocytes and elevated levels of CCL2/monocyte chemoattractant protein (MCP)-1, CCL5/regulated upon activation, normal T cell expressed and secreted, TNF-α and transforming growth factor-β1, and pulmonary fibrosis. Administration of evasin-1 on a preventive (from the day of bleomycin administration) or therapeutic (from Day 8 after bleomycin) schedule decreased number of leukocytes in the lung, reduced levels of TNF-α and transforming growth factor-β1, and attenuated lung fibrosis. These protective effects were similar to those observed in CCL3/MIP-1α-deficient mice. In conclusion, targeting CCL3/MIP-1α by treatment with evasin-1 is beneficial in the context of bleomycin- induced lung injury, even when treatment is started after the fibrogenic insult. Mechanistically, evasin-1 treatment was associated with decreased recruitment of leukocytes and production of fibrogenic cytokines. Modulation of CCL3/MIP-1α function by evasin-1 could be useful for the treatment of idiopathic pulmonary fibrosis.


Braunersreuther V.,University of Geneva | Pellieux C.,University of Geneva | Pelli G.,University of Geneva | Burger F.,University of Geneva | And 8 more authors.
Journal of Molecular and Cellular Cardiology | Year: 2010

Although beneficial for cardiomyocyte salvage and to limit myocardial damage and cardiac dysfunction, restoration of blood flow after prolonged ischemia exacerbates myocardial injuries. Several deleterious processes that contribute to cardiomyocyte death have been proposed, including massive release of reactive oxygen species, calcium overload and hypercontracture development or leukocyte infiltration within the damaged myocardium. Chemokines are known to enhance leukocyte diapedesis at inflammatory sites. The aim of the present study was to investigate the effect of chemokine CCL5/RANTES antagonism in an in vivo mouse model of ischemia and reperfusion. ApoE-/- mice were submitted to 30 min ischemia, by ligature of the left coronary artery, followed by 24 h reperfusion. Intraperitoneal injection of 10 μg of CCL5/RANTES antagonist [44AANA47]-RANTES, 5 min prior to reperfusion, reduced infarct size as well as Troponin I serum levels compared to PBS-treated mice. This beneficial effect of [44AANA47]-RANTES treatment was associated with reduced leukocyte infiltration into the reperfused myocardium, as well as decreased chemokines Ccl2/Mcp-1 and Ccl3/Mip-1α expression, oxidative stress, and apoptosis. However, mice deficient for the CCL5/RANTES receptor Ccr5 did not exhibit myocardium salvage in our model of ischemia-reperfusion. Furthermore, [44AANA47]-RANTES did not mediate cardioprotection in these ApoE-/- Ccr5-/- deficient mice, probably due to enhanced expression of compensatory chemokines. This study provides the first evidence that inhibition of CCL5/RANTES exerts cardioprotective effects during early myocardial reperfusion, through its anti-inflammatory properties. Our findings indicate that blocking chemokine receptor/ligand interactions might become a novel therapeutic strategy to reduce reperfusion injuries in patients during acute coronary syndromes. © 2009 Elsevier Ltd. All rights reserved.


Krohn S.C.,Merck Serono Geneva Research Center | Bonvin P.,Merck Serono Geneva Research Center | Bonvin P.,NovImmune | Proudfoot A.E.I.,Merck Serono Geneva Research Center
PLoS ONE | Year: 2013

CCL18 has been reported to be present constitutively at high levels in the circulation, and is further elevated during inflammatory diseases. Since it is a rather poor chemoattractant, we wondered if it may have a regulatory role. CCL18 has been reported to inhibit cellular recruitment mediated by CCR3, and we have shown that whilst it is a competitive functional antagonist as assessed by Schild plot analysis, it only binds to a subset of CCR3 receptor populations. We have extended this inhibitory activity to other receptors and have shown that CCL18 is able to inhibit CCR1, CCR2, CCR4 and CCR5 mediated chemotaxis, but has no effect on CCR7 and CCR9, nor the CXC receptors that we have tested. Whilst CCL18 is able to bind to CCR3, it does not bind to the other receptors that it inhibits. We therefore tested the hypothesis that it may displace glycosaminoglycan (GAG) chemokines bound either in cis- on the leukocyte, or in trans-presentation on the endothelial surface, thereby inhibiting the recruitment of leukocytes into the site of inflammation. We show that CCL18 selectivity displaces heparin bound chemokines, and that chemokines from all four chemokine sub-classes displace cell bound CCL18. We propose that CCL18 has regulatory properties inhibiting chemokine function when GAG-mediated presentation plays a role in receptor activation. © 2013 Krohn et al.

Discover hidden collaborations