Abnormal migration phenotype of mitogen-activated protein kinase-activatedprotein kinase 2(-/-) neutrophils in Zigmond chambers containing formyl-methionyl-leucyl-phenylalanine gradients

Time-lapsed video microscopy and confocal imaging were used to study the mi gration of wild-type (WT) and mitogen-activated protein kinase-activated pr otein kinase 2 (MK2)(-/-) mouse neutrophils in Zigmond chambers containing fMLP gradients. Confocal images of polarized WT neutrophils showed an intra cellular gradient of phospho-MK2 from the anterior to the posterior region of the neutrophils. Compared with WT neutrophils, MK2(-/-) neutrophils show ed a partial loss of directionality but higher migration speed. Immunoblott ing experiments showed a lower protein level of p38 mitogen-activated prote in kinase and a loss of fMLP-induced extracellular signal-related kinase ph osphorylation in MK2(-/-) neutrophils. These results suggest that MK2 plays an important role in the regulation of neutrophil migration and may also a ffect other signaling molecules.