LTD4 is known to prime alveolar macrophages
to produce mediators such as MIP-1α, TNF and NO when stimulated with LPS [35]. In our study, sCD14 production in PBMC-CD14+ cultures was blocked by the co-incubation of LTD4 with the LTRA Montelukast. This observation supports the hypothesis that LTRAs could exert some of their anti-inflammatory effects by inhibiting LPS-induced augmentation of the asthmatic inflammation. This is further supported by previous reports where the LTRA pranlukast was able to suppress NF-κ activation, an intracellular signalling pathway which is also activated by LPS in human monocytes/macrophages as well as by Tcells find more [51]. In our study, there was a trend towards an increase
in sCD14 production in PBMC-CD14+ Protein Tyrosine Kinase inhibitor cultures following stimulation with LPS and the combination of LPS and LTD4 that, however, failed to reach statistical significance, possibly as a result of a relatively short stimulation interval, as in vivo the maximal sCD14 concentrations were measured 42–44 h after allergen and LPS stimulation [44], respectively. Therefore, we cannot rule out that a more prolonged stimulation of PBMC-CD14+ cultures might have resulted in a significant increase in sCD14 production. In conclusion, kinetic analysis of the local endobronchial sCD14 production suggests that sCD14 concentrations reach their maximum around 42 h after segmental allergen challenge. We provide evidence that LTD4 stimulates sCD14 production in PBMC-CD14+ cultures which could contribute to the proinflammatory potential of this mediator. The leukotriene-receptor antagonist Montelukast is able to block this effect, suggesting that this is indeed a CysLTR-1 mediated effect. As LPS seem to have a protective role in the development of asthma on the one hand [1], possibly related to LPS dose and genetic constellation Immune system [2, 4], it can aggravate existing asthma
on the other hand [3]. Based on our in vitro findings, it could be speculated that leukotriene-receptor antagonists might be able to block the effects of LPS-induced aggravation of allergic asthma in vivo. “
“Mucosal leishmaniasis (ML) is characterised by severe tissue destruction. Herein, we evaluated the involvement of the IL-17-type response in the inflammatory infiltrate of biopsy specimens from 17 ML patients. IL-17 and IL-17-inducing cytokines (IL-1β, IL-23, IL-6 and TGF-β) were detected by immunohistochemistry in ML patients. IL-17+ cells exhibited CD4+, CD8+ or CD14+ phenotypes, and numerous IL-17+ cells co-expressed the CC chemokine receptor 6 (CCR6). Neutrophils, a hallmark of Th17-mediated inflammation, were regularly detected in necrotic and perinecrotic areas and stained positive for neutrophil elastase, myeloperoxidase and MMP-9.