CPG DNA, A NOVEL IMMUNE ENHANCER FOR SYSTEMIC AND MUCOSAL IMMUNIZATION WITH INFLUENZA-VIRUS

Bacterial DNA causes B cell proliferation, immunoglobulin secretion, a nd Th1-like cytokine secretion due to unmethylated CpG dinucleotides i n particular base contexts (CpG motifs), which are fnr move common in bacterial DNA than in vertebrate DNA, Synthetic oligodeoxynucleotides (ODN) containing CpG motifs also trigger immune activation suggesting possible utility as vaccine enhancers, Mice systemically primed with f ormalin-inactivated influenza virus mixed with CpC ODN generated virus -specific serum antibodies at titres approximately seven times higher than mice immunized without CpG the titres were further increased foll owing an identical second injection. To determine whether CpG could be absorbed through mucosae and enhance vaccination responses, mice were immunized intranasally (IN) with the same preparation of virus with o r without CpG ODN or Escherichia coli DNA, Following IN immunization, CpG ODN or E, coli DNA promoted increased production of influenza-spec ific antibodies in serum, saliva and the genital tract, compared with the control groups, These studies indicate that stimulatory CpG ODN ar e promising new immune enhancers for vaccination applications, Publish ed by Elsevier Science Ltd.