title: Granulocyte plasma membrane damage by leukotoxic supernatant from Pasteurella haemolytica A1 and protection by immune serum.
abstract: Bovine respiratory disease caused by Pasteurella haemolytica may be partially mediated by a leukotoxin secreted by the microorganism. We examined the effect of leukotoxic Pasteurella supernatants on leakage of the cytosol enzyme lactate dehydrogenase and the lysosomal enzyme arylsulfatase from bovine granulocytes. Lactate dehydrogenase release (94%) was much higher than arylsulfatase release (38%) over 30 minutes of incubation. The Pasteurella supernatants inhibited superoxide production by stimulated granulocytes at concentrations which also caused substantial cell death as measured by failure to exclude trypan blue. Both toxic effects were prevented by serum from aerosol-immunized calves, and protection appeared to be antibody-specific by comparison with fetal bovine serum or with serum absorbed against intact P. haemolytica. These findings suggest that the leukotoxin may selectively disrupt the granulocyte plasma membrane, and that antibody directed against a surface component of the microorganism is also capable of protecting against the leukotoxin effect.
authors.affiliation: Department of Medicine, Michigan State University, East Lansing 48824.
authors.forename: B
authors.initials: B
authors.lastname: Styrt
authors.forename: R D
authors.initials: RD
authors.lastname: Walker
authors.forename: J C
authors.initials: JC
authors.lastname: White
authors.forename: L D
authors.initials: LD
authors.lastname: Dahl
authors.forename: J C
authors.initials: JC
authors.lastname: Baker
mesh_terms: D000818:Animals; D001192:Arylsulfatases / Q000097:blood; D001427:Bacterial Toxins / Q000494:pharmacology*; D002417:Cattle / Q000097:blood*; D002462:Cell Membrane / Q000187:drug effects; D003603:Cytotoxins / Q000494:pharmacology*; D005098:Exotoxins / Q000494:pharmacology*; D006098:Granulocytes / Q000187:drug effects* / Q000201:enzymology; D007106:Immune Sera / Q000494:pharmacology*; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000097:blood; D010325:Pasteurella
chemical_list: D001427:Bacterial Toxins; D003603:Cytotoxins; D005098:Exotoxins; D007106:Immune Sera; C018579:leukotoxin; D007770:L-Lactate Dehydrogenase; D001192:Arylsulfatases