Cryopreservable neutrophil surrogates: granule-poor, motile cytoplasts from polymorphonuclear leukocytes home to inflammatory lesions in vivo

Cytokineplasts (CKP) are anucleate, motile, granule-poor fragments induced from polymorphonuclear leukocytes on surfaces by the brief application of heat. Derived from the peripheral cytoplasm and membranes of PMN, they retain the sensing, transducing, and effector mechanisms necessary for chemotaxis and phagocytosis, and appear to represent a functional, self-purification of the motile apparatus. Unlike their parent PMN, CKP are cryopreservable. We have shown that they can adhere to endothelial cell monolayers, open interendothelial cell junctions, and migrate to the abluminal side when stimulated by a chemoattractant. Employing an animal model, we now show that, given intravenously, they can home to an inflammatory target lesion in vivo.