Effects of human IL-8 isoforms on bovine neutrophil function in vitro.
Interleukin 8 (IL-8) is a potent chemotactic and activating agent for human neutrophils and bovine IL-8 is chemotactic for bovine neutrophils; however, it is unclear whether IL-8 activates bovine neutrophils. Two isoforms of human recombinant (hr) IL-8 protein (77 and 72 amino acid) were used to stimulate bovine neutrophils in vitro. Bovine neutrophils exhibited significant migration in the presence of 0.1, 0.5, 1.0 and 5.0ngml(-1) hr IL-8 when incubated for 30min at 37 degrees C in a modified Boyden chamber assay. Both the 77 and 72 aa forms were equally effective in inducing migration in this assay. At the highest doses of IL-8 examined (1 and 5ngml(-1)), migration was similar to migration in the presence of 20% zymosan-activated serum (ZAS) or 12h lipopolysaccharide (LPS)-stimulated blood monocyte supernatants (CM). Significant (p<0. 05) release of alkaline phosphatase (ALK-P) (from specific granules) occurred but myeloperoxidase (MPO) release and superoxide anion production were not enhanced in bovine neutrophils by either form of hrIL-8 at any of the doses tested. Significant (p<0.05) alkaline phosphatase release was observed in the presence of 10 and 100ngml(-1) for the 72 aa form of IL-8 and only at the higher dose for the 77 aa form of IL-8. The ZAS and CM significantly enhanced neutrophil degranulation of ALK-P and MPO as well as inducing superoxide anion production. These results suggest that IL-8 may play a role in both neutrophil recruitment and activation during bovine inflammatory processes.
Galligan
C L
CL
Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Canada.
Coomber
B L
BL
D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D002417:Cattle / Q000276:immunology* / Q000502:physiology; D002452:Cell Count / Q000662:veterinary; D015550:Cell Degranulation / Q000276:immunology* / Q000502:physiology; D002634:Chemotaxis, Leukocyte / Q000276:immunology / Q000502:physiology; D017077:Culture Media, Conditioned; D006801:Humans; D016209:Interleukin-8 / Q000276:immunology* / Q000502:physiology; D009504:Neutrophils / Q000276:immunology* / Q000502:physiology; D009195:Peroxidase / Q000032:analysis; D020033:Protein Isoforms / Q000276:immunology / Q000502:physiology; D011994:Recombinant Proteins / Q000276:immunology; D013481:Superoxides / Q000032:analysis / Q000276:immunology; D015054:Zymosan / Q000276:immunology
D017077:Culture Media, Conditioned; D016209:Interleukin-8; D020033:Protein Isoforms; D011994:Recombinant Proteins; D013481:Superoxides; D015054:Zymosan; D009195:Peroxidase; D000469:Alkaline Phosphatase