Antigen Analysis and Restriction Fragment Length Polymorphism of the Polymerase Chain reaction Products of Varicella-Zoster Virus Wild Strains Isolated in Korea

Park, Hae Kyung; Seoh, Ju Young

Abstract

Varicella-Zoster virus (VZV) is the causative agent of chickenpox in children. It also causes herpes zoster in old or immunocompromised people. For effective control of VZV, live attenuated vaccine (Oka strain) was developed in 1974 and has been used worldwidely. This vaccine is indicated when VZV infection can be fatal, such as leukemia, with favorable success. Recently, routine usage of VZV vaccine for general young population was proposed. However, general use of vaccine requires prior epidemiological study of wild strains prevailing in the target population. In this regard, we investigated the antigenic and genetic variations, if any, between Oka strain and wild strains isolated in Korea. Six wild strains of VZV isolated from zoster patients in Korea, Ellen (the labaratory-adapted strain) and Oka (vaccine) strains were cultivated in Vero cells. After the VZV-infected Vero cells were stained with specific monoclonal antibody panel, the immunofluorescent patterns were compared. The VZV-infected Vero cells were also extracted after metabolic labelling to be immunoprecipitated with the monoclonal antibodies. However, the patterns of immunofluorescent staining and immunoprecipitation did not show any antigenic difference among wild strains and vaccine or standard strain. When the VZV gene was amplified by polymerase chain reaction using primer VZV 115953 and 116605, and the PCR products were cleaved by restriction enzymes (Taq I, Bl II, and Hpa II), two kinds of restriction patterns were observed. These results suggested that antigenic variation was not common among wild strains of VZV isolated in Korea and between vaccine strain. But the different restriction patterns implied potential antigenic variation.