Hck is a Src family cytoplasmic protein tyrosine kinases with roles in cellular proliferation and migration, but its involvement in lung diseases such as asthma and chronic bronchitis (COPD) was not know. In September 3 Journal of Experimental Medicine Matthias Ernst and colleagues from Ludwig Institute for Cancer Research, Royal Melbourne Hospital, Australia, show that constitutive activation of the Hck gene results in spontaneous pulmonary inflammation and an enhanced innate immune response in mice.

Ernst et al. used Hck^F/F "gain-of-function" mice and observed that these animals spontaneously developed extensive eosinophilic and mononuclear lung cell infiltration and marked epithelial mucus metaplasia in conducting airways. When challenged with lipopolysaccharide, Hck^F/F mice exhibited exaggerated pulmonary innate immune responses and their macrophages and neutrophils produced increased amounts of inflammatory mediators in vitro.

"We propose that careful and tight control of the activity of the Hck enzyme will be a critical determinant in...