Claire Y.H. HuangSiritorn ButrapetDennis J. PierroGwong Jen J. ChangAnn R. HuntNatth BhamarapravatiDuane J. GublerRichard M. KinneyNational Center for Emerging and Zoonotic Infectious DiseasesMahidol University2018-09-072018-09-072000-03-22Journal of Virology. Vol.74, No.7 (2000), 3020-30280022538X2-s2.0-0034096441https://repository.li.mahidol.ac.th/handle/20.500.14594/25989We constructed chimeric dengue type 2/type 1 (DEN-2/DEN-1) viruses containing the nonstructural genes of DEN-2 16681 virus or its vaccine derivative, strain PDK-53, and the structural genes (encoding capsid protein, premembrane protein, and envelope glycoprotein) of DEN-1 16007 virus or its vaccine derivative, strain PDK-13. We previously reported that attenuation markers of DEN-2 PDK-53 virus were encoded by genetic loci located outside the structural gene region of the PDK-53 virus genome. Chimeric viruses containing the nonstructural genes of DEN-2 PDK-53 virus and the structural genes of the parental DEN-1 16007 virus retained the attenuation markers of small plaque size and temperature sensitivity in LLC-MK2 cells, less efficient replication in C6/36 cells, and attenuation for mice. These chimeric viruses elicited higher mouse neutralizing antibody titers against DEN-1 virus than did the candidate DEN-1 PDK-13 vaccine virus or chimeric DEN-2/DEN-1 viruses containing the structural genes of the PDK-13 virus. Mutations in the envelope protein of DEN-1 PDK-13 virus affected in vitro phenotype and immunogenicity in mice. The current PDK-13 vaccine is the least efficient of the four Mahidol candidate DEN virus vaccines in human trials. The chimeric DEN-2/DEN-1 virus might be a potential DEN-1 virus vaccine candidate. This study indicated that the infectious clones derived from the candidate DEN-2 PDK-53 vaccine are promising attenuated vectors for development of chimeric flavivirus vaccines.Mahidol UniversityImmunology and MicrobiologyArticleSCOPUS10.1128/JVI.74.7.3020-3028.2000