LAUSR

Pneumonia is caused by pathobionts present in the respiratory tract, such as Streptococcus pneumoniae. In Mucosal Immunology, Mizgerd and colleagues show that resistance to pneumonia is provided by highly localized resident memory T cells (TRM cells). The authors use a heterotypic stimulation model whereby mice primed via the lungs with one strain of S. pneumoniae are protected from infection by a different serotype. Protection is dependent on IL-17+ TRM cells present in the lung parenchyma, probably through their recruitment of neutrophils. Generalized, nonspecific stimulation of innate cells and new recruitment of T cells from outside the lungs seem to be dispensable for this protection. However, protection is compartmentalized, with the TRM cells remaining local in the site of their generation. Thus, TRM cells raised in one lung lobe offer no protection to the opposite lobe. ZF Mucosal Immunol. (17 May 2017) doi:10.1038/mi.2017.43 Regulating hair growth