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, Lsp1‐/‐ neutrophils showed impairment in both migration speed and chemotaxis direction during chemokine KC‐directed chemotaxis. When examined by confocal microscopy, chemotaxing Lsp1‐/‐ 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.