Receptor-mediated binding of Pasteurella multocida dermonecrotic toxin to canine osteosarcoma and monkey kidney (vero) cells
Pettit, R.K.; Ackermann, M.R.; Rimler, R.B.
Laboratory Investigation; A Journal of Technical Methods and Pathology 69(1): 94-100
1993
ISSN/ISBN: 0023-6837 PMID: 8392646 Document Number: 419457
Binding and internalization of P. multocida dermonecrotic toxin (PMDT) by toxin-sensitive canine osteosarcoma and monkey kidney (vero) cells was examined ultrastructurally. Purified PMDT was conjugated to 20 nm colloidal gold particles, in order to observe binding and internalization in the 2 cell lines at the ultrastructural level. The effects of various compounds on PMDT-Vero binding were investigated. Colloidal gold-labelled PMDT was located at cell surfaces within 1 min of its addition and rapidly transported to coated and noncoated invaginations of the plasma membrane. After extended incubation, gold particles were observed in endocytic vesicles, but not in any other intracellular structures. The magnitude of gold-PMDT cell association correlated with the cytotoxic sensitivity of the 2 cell lines. Early, but not late, addition of the lysosomotropic agent methylamine protected vero cells from the cytotoxic effects of PMDT without affecting binding. Biochemical and ultrastructural inhibition studies suggested the requirement for a ganglioside-type vero cell receptor. This is the first report describing binding and internalization of PMDT in host cells. Biochemical and ultrastructural results suggest that PMDT interacts with a ganglioside-type receptor on vero cells and is transported to the cytosol in endocytic vesicles which do not appear to fuse with lysosomes.