title: Generation and preclinical immunogenicity study of dengue type 2 virus-like particles derived from stably transfected mosquito cells.
abstract: Recent phase IIb/III trials of a tetravalent live attenuated vaccine candidate revealed a need for improvement in the stimulation of protective immunity against diseases caused by dengue type 2 virus (DENV-2). Our attempts to develop particulate antigens for possibly supplementing live attenuated virus preparation involve generation and purification of recombinant DENV-2 virus-like particles (VLPs) derived from stably (prM+E)-expressing mosquito cells. Two VLP preparations generated with either negligible or enhanced prM cleavage exhibited different proportions of spherical particles and tubular particles of variable lengths. In BALB/c mice, VLPs were moderately immunogenic, requiring adjuvants for the induction of strong virus neutralizing antibody responses. VLPs with enhanced prM cleavage induced higher levels of neutralizing antibody than those without, but the stimulatory activity of both VLPs was similar in the presence of adjuvants. Comparison of EDIII-binding antibodies in mice following two adjuvanted doses of these VLPs revealed subtle differences in the stimulation of anti-EDIII binding antibodies. In cynomolgus macaques, VLPs with enhanced prM cleavage augmented strongly neutralizing antibody and EDIII-binding antibody responses in live attenuated virus-primed recipients, suggesting that these DENV-2 VLPs may be useful as the boosting antigen in prime-boost immunization. As the levels of neutralizing antibody induced in macaques with the prime-boost immunization were comparable to those infected with wild type virus, this virus-prime VLP-boost regimen may provide an immunization platform in which a need for robust neutralizing antibody response in the protection against DENV-2-associated illnesses could be tested.
authors.affiliation: Medical Biotechnology Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok 10700, Thailand.
authors.forename: Amporn
authors.initials: A
authors.lastname: Suphatrakul
authors.affiliation: Medical Science Research Equipment Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
authors.forename: Thippawan
authors.initials: T
authors.lastname: Yasanga
authors.affiliation: Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
authors.forename: Poonsook
authors.initials: P
authors.lastname: Keelapang
authors.affiliation: Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
authors.forename: Rungtawan
authors.initials: R
authors.lastname: Sriburi
authors.affiliation: Medical Biotechnology Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok 10700, Thailand; Dengue Hemorrhagic Fever Research Unit, Office of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
authors.forename: Thaneeya
authors.initials: T
authors.lastname: Roytrakul
authors.affiliation: Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom 73170, Thailand.
authors.forename: Rojjanaporn
authors.initials: R
authors.lastname: Pulmanausahakul
authors.affiliation: Research Institute for Health Sciences, Chiang Mai University, Chiang Mai 50200, Thailand.
authors.forename: Utaiwan
authors.initials: U
authors.lastname: Utaipat
authors.affiliation: Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
authors.forename: Yanee
authors.initials: Y
authors.lastname: Kawilapan
authors.affiliation: Medical Biotechnology Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok 10700, Thailand; Dengue Hemorrhagic Fever Research Unit, Office of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
authors.forename: Chunya
authors.initials: C
authors.lastname: Puttikhunt
authors.affiliation: Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand; Biomedical Technology Research Center, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency at the Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand.
authors.forename: Watchara
authors.initials: W
authors.lastname: Kasinrerk
authors.affiliation: Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom 73170, Thailand.
authors.forename: Sutee
authors.initials: S
authors.lastname: Yoksan
authors.affiliation: Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom 73170, Thailand.
authors.forename: Prasert
authors.initials: P
authors.lastname: Auewarakul
authors.affiliation: Medical Biotechnology Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok 10700, Thailand; Dengue Hemorrhagic Fever Research Unit, Office of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
authors.forename: Prida
authors.initials: P
authors.lastname: Malasit
authors.affiliation: Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand. Electronic address: nicha@kku.ac.th.
authors.forename: Nicha
authors.initials: N
authors.lastname: Charoensri
authors.affiliation: Medical Biotechnology Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok 10700, Thailand; Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand. Electronic address: nopporn.sittiso@cmu.ac.th.
authors.forename: Nopporn
authors.initials: N
authors.lastname: Sittisombut
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D000917:Antibody Formation; D009033:Culicidae / Q000166:cytology; D003715:Dengue / Q000517:prevention & control*; D053059:Dengue Vaccines / Q000008:administration & dosage / Q000276:immunology*; D003716:Dengue Virus; D005260:Female; D008252:Macaca fascicularis; D008297:Male; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D014162:Transfection; D058425:Vaccines, Virus-Like Particle / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D053059:Dengue Vaccines; D058425:Vaccines, Virus-Like Particle
keywords: Dengue; Dengue vaccines; Immunogenicity; Virus-like particles