| Project/Area Number |
16590055
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biological pharmacy
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| Research Institution | University of Shizuoka |
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Principal Investigator |
IMAI Yasuyuki University of Shizuoka, School of Pharmaceutical Sciences, Professor, 薬学部, 教授 (80160034)
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| Co-Investigator(Kenkyū-buntansha) |
KUROHANE Kohta University of Shizuoka, School of Pharmaceutical Sciences, Research Associate, 薬学部, 助手 (90333525)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2004: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | therapeutic antibodies / IgA / mucosal immunity / Shiga toxin / monoclonal antibodies / carbohydrate recognition |
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| Research Abstract |
Antibodies of IgA class that can be orally administered and act on the mucosal surface may be useful as therapeutic antibodies. Mice were intranasally immunized to obtain sufficient IgA response, and then IgA monoclonal antibodies were produced by the use of nasal-associated lymphoid tissue (NALT). As an antigen, we expressed and purified recombinant Shiga toxin B subunits (Stx1B) that are responsible for the binding to carbohydrate ligands. Because of very low immunogenicity of Stx1B to mice, it was difficult to produce specific IgA against Stx1B. We found that chemical cross-linking, adsorption on polystyrene microspheres of appropriate size, and incorporation into liposome greatly enhanced immunogenicity of Stx1B upon mucosal immunization. An IgA mAb against Stx1B efficiently inhibited interaction between immobilized Stx1B and polymer-based carbohydrate ligands, in which globotriose is present on the poly-lysine backbone. In contrast, the same mAb partially inhibited the binding of soluble Stx1B to the cell surface natural ligands. To investigate this difference, we examined binding of soluble Stx1B to the immobilized mAb IgA by means of surface plasmon resonance studies. The IgA mAb showed slower association and faster dissociation kinetics as compared with an IgG mAb that can efficiently neutralize biological activity of Stx. We cloned full-length cDNA encoding polypeptides from IgA and IgG mAbs against Stx1B to produce recombinant antibodies (including "plantibodies") in future. We were able to obtain IgA mAbs against cholera toxin and those against ovalbumin, suggesting the applicability of our procedure to produce IgA mAbs in general.
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