The carboxyterminal domains of human IFN-alpha2 and IFN-alpha8 are antigenically homologous.
The antigenic properties of human hybrid IFN-alpha8(60)/alpha1(92)/alpha8 were compared with those of human IFN-alpha1 and IFN-alpha2 using monoclonal antibodies (mAb). Hybrid IFN demonstrated a significantly closer antigenic relationship to the subtype alpha2 than to the subtype alpha1. In particular, high homology was observed between antigenic structures located in the C-terminal domains (93-166) of IFN-alpha8 and IFN-alpha2, whereas the corresponding N-terminal receptor-binding domains (30-53) showed distinct antigenic characteristics. The 100% homology between IFN-alpha8 and IFN-alpha2 in the region 114-131 (helix D) indicated the role of this region in formation of the common antigenic structure. In IFN-alpha8/1/8, this shared antigenic structure was important for antiviral activity and exhibited immunodominant properties, consistent with functional and antigenic properties of the corresponding structure in IFN-alpha2. Based on this antigenic homology, we suggest that IFN-alpha8 and IFN-alpha2 are evolutionarily more closely related to each other than to IFN-alpha1. This study will contribute to a better understanding of evolutionary events in the human IFN-alpha family.
Vancová
I
I
Institute of Virology, Slovak Academy of Sciences, Bratislava.
Kontseková
E
E
Mucha
V
V
Kontsek
P
P
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D000941:Antigens / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D018604:Epitope Mapping; D019143:Evolution, Molecular; D006801:Humans; D007370:Interferon Type I / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D016898:Interferon-alpha / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins; D017386:Sequence Homology, Amino Acid
D000911:Antibodies, Monoclonal; D000941:Antigens; D007370:Interferon Type I; D016898:Interferon-alpha; D011994:Recombinant Proteins