Inhibition of equine neutrophil chemotaxis and chemokinesis by a Taenia taeniaeformis proteinase inhibitor, taeniaestatin

Taeniaestatin, a recently isolated Taenia taeniaeformis proteinase inhibitor, was used to inhibit equine neutrophil migration. Taeniaestatin itself was not chemotactic when used as a chemotactic factor but taeniaestatin did inhibit neutrophil chemokinesis when tested in a Zigmond-Hirsch checkerboard assay. A dose-dependent inhibition of both chemokinesis and chemotaxis was observed when zymosan activated bovine sera (ZABS) was used as the chemotactic factor. This inhibition was greater than 95% when 5 mu of taeniaestatin was present on both the cell and chemotactic factor side of the chambers. Equine neutrophils gave dose- and time-dependent migration responses to purified bovine C5a with an ED50 of 1.04 X 10(-7)M. Taeniaestatin inhibited the C5a-mediated chemotactic and chemokinetic neutrophil responses (51% using 1 mu and greater than 95% with 5 mu of taeniaestatin). The inhibition of leucocyte motility by taeniaestatin was reversible and without cytotoxicity at the highest doses of taeniaestatin tested.