Deng, Q., Sarris, M., Bennin, D.A., Green, J.M., Herbomel, P., and Huttenlocher, A. (2013) Localized bacterial infection induces systemic activation of neutrophils through Cxcr2 signaling in zebrafish. Journal of Leukocyte Biology. 93(5):761-9.
Neutrophils are the first line of defense against tissue damage and are rapidly mobilized to sites of bacterial infection.
However, the signals that regulate neutrophil recruitment are not well defined. Here, using photolabel-enabled fate mapping
in zebrafish larvae, we show that localized otic infection with Pseudomonas aeruginosa induces systemic activation and mobilization of neutrophils from the CHT through Cxcr2 signaling. We have cloned the zebrafish
Cxcr1 and Cxcr2 receptors and show that Cxcr2 functions as a Cxcl8 receptor in live zebrafish. With the use of morpholino-mediated
depletion, we show that infection-induced neutrophil mobilization from the CHT is mediated by Cxcr2 but not Cxcr1. By contrast,
Cxcr2 depletion does not affect neutrophil recruitment to the chemoattractant LTB4. Taken together, our findings identify Cxcl8-Cxcr2 signaling as an infection-induced long-range cue that mediates neutrophil
motility and mobilization from hematopoietic tissues, positioning Cxcr2 as a critical pathway that mediates infection-induced
systemic activation of neutrophils.