Role of arginase 1 in lung protective immunity against Streptococcus pneumoniae in mice

Type 2 helper cell (TH2) dominated chronic lung diseases like asthma are associated with an increased risk for bacterial lung infections. However, the underlying mechanisms are poorly defined. Arginase 1 has been suggested to play an important role in the pathophysiology of asthma, and is rapidly induced in lung macrophages by TH2 cytokines, thereby limiting macrophage-derived antimicrobial nitric oxide (NO) production. However, the interplay between TH2 cytokine-dependent upregulation of Arg1 and its effect on lung protective immunity against bacterial infection has not been examined in detail. We here examined…