An Anti-Interleukin 8 Monoclonal Antibody That Interferes with the Binding of Interleukin 8 to Cellular Receptors and the Activation of Human Blood Neutrophils

Publisher Website
Google Scholar
Abstract
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 107 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.

This publication has 41 references indexed in Scilit: