Polypeptides and functions of antigens from human coronaviruses 229E and OC43

Abstract

Coronaviruses possess 3 major size classes of polypeptides as judged by MW .apprx. 180,000, .apprx. 50,000 and .apprx. 23,000. Human coronaviruses 229E and OC43 possess not only 3 similar size classes of polypeptides but also 3 distinct antigens, none of which cross-react with the heterologous strain. Polypeptides separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were reacted in rocket immunoelectrophoresis with antiserum monospecific to each of the 3 strain-specific antigens (excised precipitin lines from crossed immunoelectrophoresis profiles were used for immunogens). Monospecific antiserum with neutralizing ability reacted with a polypeptide of 186,000 daltons for 229E and a polypeptide of 190,000 daltons for OC43. The antigen which elicited neutralizing antibody response was located at the surface, associated with the corona of the virion, glycosylated and bound by concanavalin A. Another less prominent surface antigen was represented by size classes of 23,000 daltons for 229E and 24,000 for OC43. The core antigens of the viruses had MW of 49,000 for 229E and 52,000 for OC43 virus. Thus, the MW and functions of the antigens of human coronaviruses are similar to those of animal coronaviruses. The polypeptides of coronaviruses 229E and OC43 are nearly identical as judged by MW, but the similar polypeptides of the 2 viruses represent different immunological specificities.