An anti-interleukin 8 monoclonal antibody that interferes with the binding of interleukin 8 to cellular receptors and the activation of human blood neutrophils.
Interleukin 8 (IL-8) is a proinflammatory cytokine produced by a wide variety of cells. Interleukin 8 acts as a neutrophil activator and chemotactic factor. In the current studies, we examined the properties of a monoclonal antibody against human IL-8. The estimated affinity of the antibody was 1.74 x 10(7) liters/mol. The antibody interfered with the binding of radiolabeled recombinant human IL-8 (rhIL-8) to human blood neutrophils (IC50 = 3 x 10(-7) M, at an IL-8 concentration of 2.4 nM). Neutrophil degranulation elicited by 5 x 10(-6)-4 x 10(-8) M rhIL-8 was blocked by the antibody at three-fold molar excess. However, a higher concentration of anti-IL-8 antibody was needed to suppress the chemotactic activity of rhIL-8. The inhibition of neutrophil chemotaxis triggered by 2 x 10(-7)-2 x 10(-9) M rhIL-8 required 6 x 10(-5) M antibody. Similarly, a 300-fold molar excess of anti-IL-8 antibody [10(-5) M] was necessary to abrogate the increase in cytosolic free calcium in neutrophils stimulated with 4 x 10(-8) M rhIL-8. In addition, epitope analysis using synthetic peptides corresponding to different regions of the IL-8 molecule showed that peptide consisting of residues 44-72 (corresponding to the C-terminal of the IL-8 molecule) competed with the antibody for binding to rhIL-8. Because IL-8 is an important inflammatory mediator in several human diseases, anti-IL-8 antibodies may have pharmacological potential.
Kurdowska
A
A
Department of Biochemistry, University of Texas, Health Center, Tyler 75710, USA.
Miller
E J
EJ
Cohen
A B
AB
D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000494:pharmacology*; D000915:Antibody Affinity; D015703:Antigens, CD / Q000187:drug effects / Q000276:immunology*; D001667:Binding, Competitive; D002118:Calcium / Q000378:metabolism; D002634:Chemotaxis, Leukocyte / Q000276:immunology; D006801:Humans; D016209:Interleukin-8 / Q000037:antagonists & inhibitors / Q000276:immunology* / Q000378:metabolism; D018375:Neutrophil Activation / Q000187:drug effects; D009504:Neutrophils / Q000201:enzymology / Q000276:immunology*; D018123:Receptors, Interleukin / Q000187:drug effects / Q000276:immunology*; D023062:Receptors, Interleukin-8A
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D016209:Interleukin-8; D018123:Receptors, Interleukin; D023062:Receptors, Interleukin-8A; D002118:Calcium