Characterization of adenovirus hexon epitopes by monoclonal antibodies

Three-thousand hybridoma clones were produced using crystallized hexon of human adenovirus type 1 for immunization. ELISA revealed 69 homospecific antibody producing clones. The monoclonals were reactive with both crystallized and non-crystallized purified soluble hexon preparations, as well as with the hexons derived from purified virions. Hexon preparations of 10 different human adenovirus species (members of 4 different subgenera) were used for the characterization of 33 monoclonal antibodies. ELISA and passive haemagglutination (HA) tests revealed 6 and 15 distinct reactivity patterns (RP) i.e. intertype cross-reaction of a given antibody with the panel of test-antigens, respectively. Four of these RP-s were identical by both techniques. Significant quantitative differences existed between extinction values in ELISA and HA-titres. The results indicate the presence of identical epitopes as well as epitypic relationships among the hexons. The common epitopes and the epitypic relationship seem to be characterized by 16 different interspecies specificities under the experimental conditions, which are independent of subgenus boundaries and are demonstrable in different combinations on the hexons of adenovirus species belonging either to the same or to different subgenera.