Nobs SP, Pohlmeier L, Li F, et al. - Researchers investigated factors that drive occurrence of neutrophil-mediated chronic lung disease, and examined the role of GM-CSF (Granulocyte-Macrophage Colony Stimulating Factor) as a potential regulator in chronic asthma. For this purpose, they used different experimental animal models of chronic asthma as well as alveolar macrophage-reconstitution of global GM-CSF receptor knockout mice and cell-type specific knockout animals. GM-CSF signaling was identified as a critical factor regulating pulmonary accumulation of neutrophils. Lung dendritic cell antigen uptake, transport and T helper 2/T helper 17 cell priming were shown to be regulated by GM-CSF in an intrinsic fashion which subsequently drives pulmonary granulocyte recruitment as well as contributes to occurrence of airway hyperresponsiveness in chronic disease. Overall, experts recognize GM-CSF as a potentially novel treatment target in chronic lung inflammation, defining a GM-CSF-dependent lung conventional DC (dendritic cell) – T cell-neutrophil axis which drives chronic lung disease.