Production of secretory immunoglobulin A against Shiga toxin-binding subunits in mice by mucosal immunization.
The toxicity of Shiga toxins (Stx) depends on the binding of their B subunits to carbohydrate ligands on host cells. The production of antibodies against B subunits, especially immunoglobulin A (IgA) secreted on the mucosal surface, should contribute to host defense. One of the major problems in attempts to produce IgA against Stx was the poor immunogenicity of B subunits. We were able to produce serum IgA as well as IgG against Stx1B in mice of the H-2d haplotype by means of intranasal immunization with recombinant B subunits of Stx (Stx1B) together with cholera toxin as a mucosal adjuvant. Secretory IgA (S-IgA) was detected in nasal washes but not in feces. We prepared chemically cross-linked Stx1B for use as an immunogen, and the formation of stable oligomers was revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry. When the cross-linked Stx1B was used together with cholera toxin for the intranasal immunization of BALB/c mice, strong enhancement of the immune response was observed. The S-IgA titers in nasal washes were 16- to more than 64-fold higher than those in mice immunized with native Stx1B plus cholera toxin. Furthermore, fecal IgA was detectable when the cross-linked Stx1B was used. The use of cholera toxin was necessary for the induction of high titers of S-IgA in the nasal washes. However, the effect of cross-linking was dependent on the major histocompatibility complex haplotype; that is, no enhancement of IgA production was observed in C57BL/6 mice. The present results provide a practical means of producing IgA against Stx1B in BALB/c mice.
Imai
Yasuyuki
Y
Department of Microbiology and COE Program in the 21st Century, University of Shizuoka School of Pharmaceutical Sciences, Shizuoka 422-8526, Japan. imai@u-shizuoka-ken.ac.jp
Nagai
Rio
R
Ono
Yousuke
Y
Ishikawa
Tomoyuki
T
Nakagami
Hiroki
H
Tanikawa
Takashi
T
Kurohane
Kohta
K
D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D001428:Bacterial Vaccines / Q000008:administration & dosage*; D002772:Cholera Toxin / Q000494:pharmacology; D005260:Female; D018928:Immunity, Mucosal; D007114:Immunization; D007071:Immunoglobulin A, Secretory / Q000096:biosynthesis*; D007074:Immunoglobulin G / Q000097:blood; D051379:Mice; D008815:Mice, Inbred Strains; D021122:Protein Subunits; D022622:Shiga Toxin 1 / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000008:administration & dosage*
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D007071:Immunoglobulin A, Secretory; D007074:Immunoglobulin G; D021122:Protein Subunits; D022622:Shiga Toxin 1; D014614:Vaccines, Synthetic; D002772:Cholera Toxin