The role of glycosylation in determining the immunogenicity of influenza C virus glycoprotein

点击翻译按钮获取中文摘要

The aim of this study is to understand the role of glycosylation in determining the immunogenicity of influenza C virus glycoprotein, gp88. To this goal, the antigenicity of gp88 was compared with its nonglycosylated form (T76) synthesized in the presence of tunicamycin, utilizing seven monoclonal antibodies raised against gp88 of the C/Ann Arbor/1/50 strain. These monoclonal antibodies could be classified into two groups, A and B. Group A inhibits hemagglutination, hemolysis and infectivity of the virus whereas group B does not. Radioimmunoprecipitation experiments revealed that three antibodies in group B were all reactive with T76 as well as with gp88. In contrast, three out of four antibodies in group A did not precipitate T76 at all, and only a limited amount of the polypeptide was precipitated with the other antibody of this group. Western blot analysis also showed that denatured gp88 blotted on nitrocellulose was reactive with group B antibodies but not with group A. From these observations, we conclude that glycosylation of gp88 selectively influences the integrity of biologically active and conformation-dependent epitopes recognized by group A antibodies. It is reasonable to assume, therefore, that in the absence of glycosylation, the gp88 glycoprotein may fail to attain an appropriate conformation, and as a result, may be unable to elicit neutralizing antibodies.