Leukocyte-specific gene 1 protein (LSP1) is involved in chemokine KC-activated cytoskeletal reorganization in murine neutrophils in vitro

Leukocyte-specific gene 1 protein (LSP1) is a cytoskeletal-associated protein of leukocytes that in vitro cross-links F-actin into extensively branched bundles of mixed polarity. In this study, we examined chemotaxis and superoxide production in neutrophils prepared from wild-type (WT) and Lsp1 knockout mice. Compared to WT neutrophils, Ls1(-/-) neutrophils showed impairment ill both migration speed and chemotaxis direction during chemokine KC-directed chemotaxis, When examined by confocal microscopy, chemotaxing Ls1(-/-) neutrophils showed abnormal morphologies. They had discontinuous primary actin-rich cortexes and large membrane protrusions. When stimulated by phorbol 12-myristate 13-acetate (PMA), Lsp1(-/-) peritoneal neutrophils produce more superoxide than WT. The? data presented suggest that LSP1 plays important roles in the regulation of neutrophil morphology, motility, and superoxide production.