Protective Effects Of Recombinant Neurite Outgrowth Inhibitors DNA Vaccine On AD Model Mice

Alzheimer's disease is a chronic neurodegenerative disease, which causes a progressive loss in learning and memory capabilities and eventually results in dementia. The deposition of amyloid P plaques?neurofibrillary tangles and injury and lost in neuron in center nervous system are the main characteristics in AD patients. As the increasing number of old people in China. AD take more burdens on the patients's family and the whole society and this disease deserved more and more attention. However, most of the medicines used in the therapeutic of AD produce little effect on curing this disease. According to previous studies, immunotherapy of Alzheimer's disease mostly focused on decreasing amyloid?but the inflammation in the therapeutic mice brain became the obstacle of clinical use of vaccine. The olidendrocyte-and myelin-related neurite outgrowth inhibitors include Tenascin R (TN-R), Tenascin-C (TN-C), myelin-associated glycoprotein (MAG), oligodendrocyte-myelin glycoprotein(OMGP), Nogo, The receptor-type protein tyrosine phosphatase?(RPTP?). They are a group of proteins mainly inhibiting the outgrowth of neuron and axons after injury in central nevous system. They were mainly clustered in the nodes of Ranvier. APP protein was also found clustered in the nodes of Ranvier in central nervous system. We suppose NOIs interact with APP protein and change the enzymolysis of APP influencing the A?expression and the onset, development of Alzheimer's disease. What's more, the antibody of single NOI or immunization with several fagments of NOIs could promote the regeneration of neurons in central nervers system. Previous study also identify NOIs could directly or indirectly influence the expression of A?protein.We designed three recombinant DNA vaccines comprising the specific inhibitory domains of neurite outgrowth inhibitors and did preventive test in a co-transgenic mice model. The mice in vaccine group were concequently immunized every week with naked DNA vaccine though intramuscular injection. The blood was collected and antibody was detected by Elisa test. Morris Water Maze was used to test the learing and memory ability. Immunohistochemistry test was used to test the deposition numbers and area taken up of A?in hippocampus and cortex. The better effect of preventive vaccine PcDNA-V2 was chosen for further test. We also find the naked DNA immunization tragedy evoked low level antibody. So we construct the vaccinia virus vaccine and immunized the mice by co-immunization of DNA and vaccinia virus vaccine. Blood of immunized mice in each group were collected. Open filed test. Morris Water Maze and new object recognition test were used to test the learing and memory ability and mood behavior changes in every group. Elisa test was used to examine the expression of A?42 and 40 total proteins. Immunohistochemistry test was used to test the deposition numbers and area taken up of A?in hippocampus and cortex. Western-blot was appling to detect the expression of soluble A?oligomer. Immunohistochemistry and HE were used to test if there any inflammation in the brain of immunized mice. Western blot was used to exmine the expression of NOIs in the APP/PS1 co-transgenic mice over-expressing APP protein.PcDNA-V2 showed an effection of decreasing the expression of A?deposition in the naked DNA vaccine test. The vaccinia virus vaccine of PcDNA-V2 was contructed. DNA prime boost vaccination tragedy induced strong immune responses and effective antibodies against the four fragments in immune serum of treated mice by DNA prime-vaccinia virus boost regimen. Vaccines prevented neurons necrosis and axonal injury in the brains of treated model mice and protected the model mice from behavioral deficits. It also decreased the ratio of A?42 to A?40 in co-transgenic mice brain which is thought to play an important role in the risk of AD. The deposition of A?plaques was significantly decreased in vaccine group than in the placebo and vehicle group. The soluble A?oligomer in vaccine group was decreased significantly according to IP-western result. There was no lymphocytic infiltration in brains of model mice. There was an obvious change of TN-R and OMGP protein in APP/PS1 transgenic mice.The results suggested that immunotherapy with multiple specific domains of oligodendrocyte-and-myelin-related neurite outgrowth inhibitors might be a promising approach for Alzheimer's disease and the degenerative diseases of central nervous system. The vaccine was supposed to interact with APP to infect the onset and development of Alzheimer's disease.