Modulation of human neutrophil functions in vitro by Treponema denticola major outer sheath protein.

In this study of human polymorphonuclear leukocytes (PMNs), pretreatment with Treponema denticola major outer sheath protein (Msp) inhibited formyl-methionyl-leucyl-phenylalanine (fMLP)-induced chemotaxis, phagocytosis of immunoglobulin G-coated microspheres, fMLP-stimulated calcium transients, and actin assembly. Msp neither altered oxidative responses to phorbol myristate or fMLP nor induced apoptosis. Msp selectively impairs chemotaxis and phagocytosis by impacting the PMN cytoskeleton.