Synthesis and in vitro characterization of antigen-conjugated polysaccharide as a CpG DNA carrier

Naohiko Shimada, Ken J. Ishii, Yoichi Takeda, Cevayir Coban, Yuichi Torii, Seiji Shinkai, Shizuo Akira, Kazuo Sakurai

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11 Citations (Scopus)


Oligodeoxynucleotides containing unmethylated CpG sequences (CpG DNAs) are known as an immune adjuvant. CpG DNAs coupled with a particular antigen enabling both CpG DNA and antigen delivery to the same antigen-presenting cell have been shown to be more effective. Based on our previous finding that β-(1→3)-D-glucan schizophyllan (SPG) can be used as a CpG DNA carrier, here we present the synthesis of an antigen-conjugated SPG and the characterization of the conjugate. Ovalbumin (OVA, 43 kDa) was used as a model antigen, and two OVA were conjugated to one SPG molecule (Mw = 150 000), denoted by OVA-SPG. Circular dichroism and gel electrophoresis showed that OVA-SPG could form a complex with a (dA)40-tailed CpG DNA at the 3′ end (1668-(dA)40). When OVA-SPG was added to macrophages (J774.A1), the amount of the ingested OVA-SPG was increased compared with that of OVA itself, suggesting that Dectin-1 (proinflammatory nonopsonic receptor for β-glucans) is involved to ingest OVA-SPG. Furthermore, the complex of the conjugate and DNA was co-localized in the same vesicles, implying that OVA (antigen) and CpG DNA (adjuvant) were ingested into the cell at the same time. This paper shows that OVA-SPG can be used as a CpG DNA carrier to induce antigen-specific immune responses.

Original languageEnglish
Pages (from-to)1136-1140
Number of pages5
JournalBioconjugate Chemistry
Issue number5
Publication statusPublished - 2006
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Bioengineering
  • Biomedical Engineering
  • Pharmacology
  • Pharmaceutical Science
  • Organic Chemistry


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