Prevention of neuropathic pain in an animal model of spare nerve injury following oral immunization with recombinant adenovirus serotype 5-mediated NR2B gene transfer.

Spinal N-methyl-D-aspartate receptor 2B subunit (NR2B)-increased expression plays an important role in the facilitation and maintenance of the persistent pain state due to peripheral nerve injury. A vaccination strategy to reduce the expression of brain protein is feasible and may have therapeutic potential for neurological disorders. Thus, we investigated the effect of oral immunization with recombinant adenovirus serotype 5-mediated NR2B gene transfer (rAd5/NR2B) for the modulation of neuropathic pain. After peroral administration of the rAd5/NR2B vaccine, transgene NR2B expression persisted for at least a week and was associated with the induction of high serum titers of NR2B-specific antibodies. Following the occurrence of mechanical allodynia due to peripheral nerve injury, NR2B-specific antibodies could pass the blood-brain barrier, transport and subsequently bind to the spinal NR2B protein. The humoral immunoresponse results in the strong antiallodynia in the spared nerve injury animal model. These data proved the feasibility of oral immunization with rAd5/NR2B for the prevention of neuropathic pain.