PT  - JOURNAL ARTICLE
AU  - Markus Weckmann
AU  - Gyde Nissen
AU  - Tim Becker
AU  - Elvira Ehlers-Jeske
AU  - Matthias Kopp
TI  - Complex extracellular matrix modulates neutrophil migration <em>in vitro</em>
DP  - 2014 Sep 01
TA  - European Respiratory Journal
PG  - P3862
VI  - 44
IP  - Suppl 58
4099  - http://erj.ersjournals.com/content/44/Suppl_58/P3862.short
4100  - http://erj.ersjournals.com/content/44/Suppl_58/P3862.full
SO  - Eur Respir J2014 Sep 01; 44
AB  - Background: Neutrophil inflammation in bronchial asthma is often therapy resistant and leads to severe exacerbation and hospitalization. Haldar and colleagues identified a refractory subpopulation of asthma patients (high-dose corticosteroids), whose asthma was dominated by neutrophil inflammation. The analysis of migration of neutrophil granulocytes in complex matrices has been made difficult by the lack of advanced methods for ex vivo real time analysis. We developed a novel 3D migration assay with a computerized analysis and in this study, we aimed to compare a simple matrix (fibronectin, FN) with a highly complex matrix (human placental matrix, HEM) in the presence of a corticosteroid. Methods: Neutrophil Granulocytes were isolated by density gradient centrifugation and viability, activation and eosinophil contamination were assessed. Cells were incubated with 10-6M prednisolone or vehicle for 1h and then embedded in FN or HEM on a µSlide (IBIDI). Time lapse microscopy was performed for 1h and trajectories were analyzed using an optimized algorithm. Results: Migrational speed of neutrophils in FN was 1.00 u/min whereas the more complex matrix HEM showed lower speeds (0.61 u/min). Migration in FN was more focused (directionality 0.52 vs. 0.47) towards IL-8 (Forward Migration Index = FMI FN; 0.11 vs FMI HEM: 0.079). Prednisolone results in a significant reduction of migration towards IL-8 in both matrices. Discussion: A more complex matrix such as HEM leads to a less focused and slower migration of neutrophils. This indicates that extracellular matrices from different organs could regulate neutrophil infiltration differently. Corticosteroids may not be able to alter this effect.