From bugs to drugs: Therapeutic immunomodulation with oligodeoxynucleotides containing CpG sequences from bacterial DNA

Several types of immune cells possess pattern recognition receptors (PRR) t hat can distinguish prokaryotic DNA from vertebrate DNA by detecting unmeth ylated CpG dinucleotides in particular base contexts (CpG motifs), Bacteria l DNA or synthetic oligodeoxynucleotides containing these CpG motifs activa te both innate and acquired immune responses that have evolved to protect a gainst intracellular infections, These T helper 1 (Th1)-like immune respons es include activation of B cells, dendritic cells, macrophages, and natural killer (NK) cells. CpG DNA-induced immune activation can protect against i nfection either alone or in combination with a vaccine and is effective in the immunotherapy of allergic diseases and cancer. Human clinical trials us ing such CpG DNA are currently underway.