Hepatitis e virus monoclonal antibodies or the binding fragments of it and the use thereof

An antigenic determinant selected from the antigenic determinants 1)-4) on the polypeptides encoded by HEV ORF2 consisting of the group

• 1) an antigenic determinant specifically binds the variable region of monoclonal antibody 8C11 or its analogs;
• it is exposed on the surface of hepatitis E virus particle;
• it is conformation-dependent, and correct formation and sufficient exposure of same is facilitated by the dimerization of polypeptide fragment of hepatitis E virus ORF 2;
• it partly overlaps or is adjacent to the antigenic determinant specifically recognized by monoclonal antibody 13D8;
• and it has key amino acid residues involved in the formation of said antigenic determinant which are approximately located between amino acid residue 459˜601 of hepatitis E virus ORF 2;
• or
• 2) an antigenic determinant specifically binds the variable region of the monoclonal antibody 13D8 or its analogs;
• it is exposed on the surface of hepatitis E virus particle;
• it is conformation dependent, and correct formation and sufficient exposure of the same is facilitated by the dimerization of polypeptide fragment of hepatitis E virus ORF 2;
• it partly overlaps or is adjacent to the antigenic determinant specifically recognized by monoclonal antibody 13D8;
• it has the key amino acid residues involved in the formation of said antigenic determinant which are approximately located between amino acid residue 459˜601 of hepatitis E virus ORF2;
• or
• 3) an antigenic determinant specifically binds the variable region of the monoclonal antibody 8H3 or its analogs;
• it is exposed on the surface of hepatitis E virus particle;
• it is conformation-dependent, and correct formation and sufficient exposure of the same is facilitated by the dimerization of the polypeptide fragment of hepatitis E virus ORF2;
• it has sufficient exposure and stability of spatial structure upon the binding of monoclonal antibody 8C11 to HEV and its ability of binding MAb 8H3 is remarkable enhanced thereby;
• it has the key amino acid residues involved in the formation of said antigenic determinant which are approximately located between amino acid residue 459˜601 of hepatitis E virus ORF2;
• or
• 4) an antigenic determinant specifically binds to the variable region of the monoclonal antibody 16D7 or its analogs;
• it is a linear antigenic determinant;
• it is approximately located between amino acid residue 499˜515 of hepatitis E virus ORF2.

A method for detecting antigen of hepatitis E virus and/or antibody against hepatitis E virus in samples, comprising the steps of:

• a) Providing a first and a second antibody which specifically bind hepatitis E virus, wherein at least one of said first or second antibody is monoclonal antibody or its fragment of the present invention;
• b) Providing a signal-producing agent which effectively binds the second antibody, wherein the signal intensity as produced is only dependent on the amount of the second antibody;
• or preferably, the second antibody is directly labeled with signal-producing agent;
• c) Coupling first antibody with the carrier to form the first antibody-carrier complex;
• d) Contacting the test substance with the first antibody-carrier complex, so as to bind the hepatitis E virus present in the sample, if any, to antibody-carrier complex;
• e) Contacting the second antibody effectively binding to the signal-producing agent with virus-first antibody-carrier complex, so as to form complex of signal-producing agent-second antibody-virus-first antibody-carrier;
• f) Detecting the signal produced by the signal-producing agent,
• if desired, said first antibody or second antibody may respectively be one or more of the monoclonal antibodies or their binding active fragments of this present invention, or any combination thereof.