Immunochemical characterization of antigenic domains on human interferon-beta: spatially distinct epitopes are associated with both antiviral and antiproliferative activities. Eur J Immunol 1990 Sep;20(9):1933-9
Date
09/01/1990Pubmed ID
1698636DOI
10.1002/eji.1830200910Scopus ID
2-s2.0-0025173275 (requires institutional sign-in at Scopus site) 12 CitationsAbstract
The use of a panel of monoclonal antibodies (mAb) raised against recombinant (serine-17) human interferon-beta (rHuIFN-beta ser) has permitted the identification of three epitopes on HuIFN-beta, designated as sites I, II and III, based solely on functional differences, i.e., the neutralization of antiviral and antiproliferative activities of natural and recombinant HuIFN-beta (Redlich, P.N. and Grossberg, S. E., J. Immunol. 1989. 143: 1887). Site I- and II-directed mAb possessed neutralizing activity whereas none was noted by mAb recognizing site III. To characterize further these epitopes by immunochemical means, we studied their (a) spatial relationship by competitive binding assays, (b) antigenic structure by Western blotting, and (c) sensitivity to chemical modification by the measurement of mAb reactivity after radioiodination. Competitive antibody binding studies revealed site II to be spatially distinct from sites I and III. Furthermore, site I- and II-directed mAb could easily recognize rHuIFN-beta ser on a Western blot, suggesting that both these epitopes are primarily sequential in structure or denaturation resistant. Chemical modification by radioiodination, which did not alter the biologic activity of rHuIFN-beta ser, had likewise little effect on mAb reactivity to site I; however, reactivity to site II was diminished and reactivity to site III was minimal following the radioiodination process. Both site I- and II-directed mAb inhibited the binding of 125I-rHuIFN-beta ser to intact Daudi cells, suggesting that inhibition of receptor binding is their mechanism of neutralization. Thus, we conclude that epitopes I and II, which are associated with both antiviral and antiproliferative activities of rHuIFN-beta, are spatially and immunochemically distinct.
Author List
Redlich PN, Grossberg SEAuthor
Philip N. Redlich MD, PhD Professor in the Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Antibodies, MonoclonalAntiviral Agents
Cell Division
Epitopes
Humans
Interferon Type I
Interferon beta-1a
Interferon beta-1b
Interferon-beta
Iodine Radioisotopes
Protein Conformation
Radioligand Assay
Recombinant Proteins
