title: CpG DNA, liposome and refined antigen oral cholera vaccine.
abstract: An oral cholera vaccine made up of three Vibrio cholerae antigens, i.e. lipopolysaccharide (LPS), recombinant toxin co-regulated pili (rTcpA) and heat-treated cholera toxin (H-CT) has been developed in six different formulations. Eight-week-old Wistar rats were divided into nine groups and immunized as follows: the first group received the oral vaccine 1 consisting of the three antigens (LPS, rTcpA and H-CT) associated with a liposome (L) and bacterial CpG-DNA (ODN#1826). The rats of groups 2 and 3 received oral vaccines 2 and 3 consisting of the liposome-associated three antigens with and without non-bacterial CpG-DNA (ODN#1982), respectively. Rats of groups 4 received oral vaccine 4 consisting of the three antigens mixed with the ODN#1826, similar to vaccine 1, but without liposome. Rats of groups 5 and 6 received oral vaccines 5 and 6 consisting of the three antigens with and without ODN#1982, respectively, similar to vaccines 2 and 3, but without liposome. Rats of groups 7, 8 and 9 received oral placebos, namely liposomes (L), ODN#1826 (CpG), and vaccine diluent, i.e. 5% NaHCO3 solution, respectively. All vaccines were given in three doses at 14-day intervals. It was found that the combination of liposome and ODN#1826 in vaccine 1 evoked the highest immune response to V. cholerae antigen compared to other vaccine formulations and placebos, as measured by the appearance of antigen-specific antibody-producing cells in the intestinal lamina propria. The immunogenicity according to the magnitude of the immune response was: V1>V2=V3>V4>V5=V6>V7=V8=V9. The results of this study indicate that CpG-DNA and liposome are effective mucosal adjuvants for an oral cholera vaccine prepared from refined V. cholerae antigens and their combination seems to be synergistic. The potential role of liposome as a vaccine delivery vehicle has been confirmed.
authors.affiliation: Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Ratree
authors.initials: R
authors.lastname: Leelawongtawon
authors.forename: Srinuan
authors.initials: S
authors.lastname: Somroop
authors.forename: Urai
authors.initials: U
authors.lastname: Chaisri
authors.forename: Pongsri
authors.initials: P
authors.lastname: Tongtawe
authors.forename: Manas
authors.initials: M
authors.lastname: Chongsa-nguan
authors.forename: Thareerat
authors.initials: T
authors.lastname: Kalambaheti
authors.forename: Pramuan
authors.initials: P
authors.lastname: Tapchaisri
authors.forename: Sathit
authors.initials: S
authors.lastname: Pichyangkul
authors.forename: Yuwaporn
authors.initials: Y
authors.lastname: Sakolvaree
authors.forename: Hisao
authors.initials: H
authors.lastname: Kurazono
authors.forename: Hideo
authors.initials: H
authors.lastname: Hayashi
authors.forename: Wanpen
authors.initials: W
authors.lastname: Chaicumpa
mesh_terms: D000276:Adjuvants, Immunologic; D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D000942:Antigens, Bacterial / Q000008:administration & dosage* / Q000276:immunology; D002771:Cholera / Q000517:prevention & control*; D022121:Cholera Vaccines / Q000008:administration & dosage* / Q000276:immunology; D018899:CpG Islands / Q000235:genetics*; D004247:DNA / Q000008:administration & dosage* / Q000276:immunology; D006801:Humans; D018928:Immunity, Mucosal; D007114:Immunization; D008081:Liposomes / Q000008:administration & dosage* / Q000276:immunology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014734:Vibrio cholerae / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D022121:Cholera Vaccines; D008081:Liposomes; D004247:DNA