title: A rice-based oral cholera vaccine induces macaque-specific systemic neutralizing antibodies but does not influence pre-existing intestinal immunity.
abstract: We previously showed that oral immunization of mice with a rice-based vaccine expressing cholera toxin (CT) B subunit (MucoRice-CT-B) induced CT-specific immune responses with toxin-neutralizing activity in both systemic and mucosal compartments. In this study, we examined whether the vaccine can induce CT-specific Ab responses in nonhuman primates. Orally administered MucoRice-CT-B induced high levels of CT-neutralizing serum IgG Abs in the three cynomolgus macaques we immunized. Although the Ab level gradually decreased, detectable levels were maintained for at least 6 mo, and high titers were rapidly recovered after an oral booster dose of the rice-based vaccine. In contrast, no serum IgE Abs against rice storage protein were induced even after multiple immunizations. Additionally, before immunization the macaques harbored intestinal secretory IgA (SIgA) Abs that reacted with both CT and homologous heat-labile enterotoxin produced by enterotoxigenic Escherichia coli and had toxin-neutralizing activity. The SIgA Abs were present in macaques 1 mo to 29 years old, and the level was not enhanced after oral vaccination with MucoRice-CT-B or after subsequent oral administration of the native form of CT. These results show that oral MucoRice-CT-B can effectively induce CT-specific, neutralizing, serum IgG Ab responses even in the presence of pre-existing CT- and heat-labile enterotoxin-reactive intestinal SIgA Abs in nonhuman primates.
authors.affiliation: Division of Mucosal Immunology, Department of Microbiology and Immunology, University of Tokyo, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Nochi
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Yuki
authors.forename: Yuko
authors.initials: Y
authors.lastname: Katakai
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shibata
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tokuhara
authors.forename: Mio
authors.initials: M
authors.lastname: Mejima
authors.forename: Shiho
authors.initials: S
authors.lastname: Kurokawa
authors.forename: Yuko
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Ushio
authors.initials: U
authors.lastname: Nakanishi
authors.forename: Fumiko
authors.initials: F
authors.lastname: Ono
authors.forename: Hitomi
authors.initials: H
authors.lastname: Mimuro
authors.forename: Chihiro
authors.initials: C
authors.lastname: Sasakawa
authors.forename: Fumio
authors.initials: F
authors.lastname: Takaiwa
authors.forename: Keiji
authors.initials: K
authors.lastname: Terao
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kiyono
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood* / Q000276:immunology; D057134:Antibodies, Neutralizing / Q000097:blood*; D002772:Cholera Toxin / Q000276:immunology* / Q000378:metabolism; D022121:Cholera Vaccines / Q000276:immunology*; D004768:Enterotoxins / Q000276:immunology; D004926:Escherichia coli / Q000276:immunology; D005260:Female; D018928:Immunity, Mucosal / Q000276:immunology; D007114:Immunization; D007070:Immunoglobulin A / Q000097:blood; D007073:Immunoglobulin E / Q000097:blood; D007422:Intestines / Q000276:immunology* / Q000382:microbiology; D008252:Macaca fascicularis / Q000276:immunology / Q000382:microbiology; D008297:Male; D051379:Mice; D012275:Oryza / Q000235:genetics / Q000276:immunology; D014734:Vibrio cholerae / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D057134:Antibodies, Neutralizing; D022121:Cholera Vaccines; D004768:Enterotoxins; D007070:Immunoglobulin A; D007073:Immunoglobulin E; D002772:Cholera Toxin