Neutrophils lay down the tracks

Abstract

T cells constantly circulate throughout the body until an invading pathogen calls them into action. Microbes often cause localized infections, so how do T cells know where to go? Lim et al . explore this question in a mouse model of influenza infection and find that neutrophils help guide the way (see the Perspective by Kiermaier and Sixt). Upon infection with this respiratory virus, neutrophils quickly traffic to the trachea. There, they lay down “tracks” enriched in proteins called chemokines, especially the chemokine CXCL12, which guide CD8 + T cells to the infected organ. Mice whose neutrophils could not lay down such tracks exhibited defects in CD8 + T cell recruitment and viral clearance. K. Lim, Y.-M. Hyun, K. Lambert-Emo, T. Capece, S. Bae, R. Miller, D. J. Topham, M. Kim, Neutrophil trails guide influenza-specific CD8 + T cells in the airways. Science 349 , aaa4352 (2015). [Abstract][Full Text] E. Kiermaier, M. Sixt, Fragmented communication between immune cells. Science 349 , 1055–1056 (2015). [Abstract][Full Text]