Mapping of an antigenic site on the nucleocapsid protein of human parainfluenza virus type 3.
Human parainfluenza virus type 3 (hPIV3) is a respiratory tract pathogen. The current study aimed to investigate immunodominant regions of hPIV3 nucleocapsid (N) protein by using monoclonal antibodies (mAbs) raised against recombinant N protein and human serum specimens from hPIV3-infected individuals. A panel of murine mAbs was generated following immunization with yeast-expressed hPIV3 N protein self-assembled to nucleocapsid-like particles. All mAbs recognized native viral nucleocapsids in hPIV3-infected cells as confirmed by an indirect immunofluorescence analysis. Antigenic sites recognized by the mAbs were mapped using recombinant overlapping N protein fragments. One major immunodominant site was identified in the carboxy-terminal region (amino acids [aa] 397-486) of hPIV3 N protein. Further analysis with smaller N protein fragments and a synthetic peptide revealed one linear epitope representing aa 437-446 of the N protein located within this antigenic site. This epitope was reactive with 46% of hPIV3 IgG-positive sera. These results suggest that the above antigenic site on the N protein is important in eliciting a humoral immune response against hPIV3.
Laboratory of Immunology and Cell Biology, Institute of Biotechnology, V. Graiciuno 8,Vilnius, Lithuania. azvirb@ibt.lt
Aurelija
A
Zvirbliene
Indre
I
Sezaite
Milda
M
Pleckaityte
Indre
I
Kucinskaite-Kodze
Mindaugas
M
Juozapaitis
Kestutis
K
Sasnauskas
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000032:analysis / Q000096:biosynthesis / Q000276:immunology; D018604:Epitope Mapping; D005260:Female; D006801:Humans; D016056:Immunodominant Epitopes / Q000032:analysis / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood; D008459:Measles virus / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D019590:Nucleocapsid Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D010224:Parainfluenza Virus 3, Human / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D010253:Respirovirus Infections / Q000097:blood / Q000276:immunology* / Q000821:virology; D016415:Sequence Alignment
D000911:Antibodies, Monoclonal; D016056:Immunodominant Epitopes; D007074:Immunoglobulin G; D019590:Nucleocapsid Proteins; D011994:Recombinant Proteins