An antigenic analysis of the adenovirus type 2 fibre polypeptide.

Twenty-seven monoclonal antisera were generated against the SDS-denatured fibre of adenovirus type 2. The antisera were characterized using radioimmune assay, fluorescent antibody tests, immune precipitation, Western blotting, haemagglutination and neutralization, and formed six groups as follows: A, type-specific neutralizing antisera which exhibited haemagglutination inhibition (Hi+); B, type-specific non-neutralizing antisera which did not exhibit haemagglutination inhibition (Hi-); C, subgroup-specific neutralizing antisera Hi+; D, a subgroup-specific neutralizing antiserum Hi-; E, subgroup-specific non-neutralizing antisera Hi-; F, a subgroup-specific neutralizing antiserum Hi- which did not react in Western blotting tests. The C-terminal 201 amino acids of the fibre were expressed in Escherichia coli and a total of six antisera from groups A, B and C recognized five epitopes carried on this region which in several models is thought to form the knob of the fibre. At least eight epitopes were expressed by the entire native fibre. The five epitopes of the C-terminal end of the fibre formed three antigenic sites. Two sites each consisted of a neutralizing type-specific and a neutralizing group-specific epitope which overlapped in position. The remaining site consisted of a type-specific, non-neutralizing epitope.