Immunological relationships between capsid components of adenoviruses of different host cell species origin.

Abstract

A comparative immunological analysis between human (types 2 to 6, 9, 11, 12, 15) and simian-monkey adenoviruses (types SA-7, SV15, SV20), selected to represent different hemagglutinating subgroups, and two canine (infectious canine hepatitis, ICH, and infectious canine laryngotracheitis, ICL) and one avian adenovirus (CELO) was undertaken using purified components and sera against these. Cross-reactions between hexons of all mammalian adenoviruses, but not the avian serotype studied, were found in complement fixation tests. Cross-absorption experiments did not indicate the presence of any antigenic specificities of hexons, unique for groups of adenoviruses of different host cell species origin. Vertex capsomers in penton hemagglutination enhancement (HE) tests, like hexons, were found to contain antigenic specificities common to adenoviruses of different mammalian host cell origin. Furthermore, using the fiber-HE test one-way or two-way cross-reactions were demonstrated in certain combinations between all fibers of mammalian adenoviruses studied. The degree of cross-reaction was more pronounced between hexons than between vertex capsomers, which in turn was more extensive than that between fibers. However, fibers of SV20 displayed a close relationship to fibers of certain members of subgroup 111 of human adenoviruses.Fractionation of soluble components of type SV20 revealed the presence of a soluble complete HA of a kind not previously encountered. It sedimented at a rate slightly lower than that of hexons and was trypsin sensitive. It is suggested to possibly represent a penton–fiber complex.