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Objective:To reduce the immunogenicity of vaccinia virus vector by replacing the D8L region, which is a neutralizing antibody epitope in vaccinia virus, with an exogenous gene.Methods:A gene fragment encoding influenza virus hemagglutinin (HA) was inserted into the D8L region to replace it using homologous recombination technique. Then, a recombinant vaccinia virus influenza vaccine was constricted. A recombinant vaccinia virus vaccine with the TK region expressing HA was used as a control. The expression of HA was validated by Western blot. BALB/c mice were immunized with the vaccines and the serum antibody titers two weeks after each immunization were evaluated by ELISA and hemagglutination inhibition assay. The protective efficacy of the recombinant vaccinia virus was assessed through a challenge experiment.Results:Western blot confirmed the successful expression of HAD8L protein in the constructed recombinant vaccines. ELISA and hemagglutination inhibition assay showed that after the primary immunization, the anti-HA antibody titer induced by the recombinant vaccinia virus with D8L region mutation was slightly higher than that induced by the vaccine with TK region mutation, and the difference was statistically significant with the increase of immunization times ( P<0.05). The recombinant vaccinia virus with D8L region mutation showed significantly lower immunogenicity than the recombinant virus with TK region mutation after the primary immunization, but there was no significant difference between them with the increase of immunization times ( P>0.05). After H1N1pdm challenge, no virus was detected in the mice immunized with the recombinant vaccinia virus with D8L region mutation and the mice showed mild lung inflammation and less tissue damage. Conclusions:This study indicated that inserting exogenous genes into the D8L region of the neutralizing antibody epitope in the vaccinia virus vector could help to reduce the immunogenicity of the vector itself and enhance the immunogenicity of the exogenous genes. This provided a reference for the use of the vaccinia virus vector as a delivery tool in the field of vaccines or gene therapy.
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@#Duchene muscular dystrophy (DMD) is a serious progressive muscular dystrophy.Reports in recent years about abnormal lipid in DMD patients have increased, yet little attention has been paid to liver lipid.This study aimed to explore the effect of dystrophin gene defect on liver lipid synthesis.7-week-old mdx male mice were used as DMD model.The conditions of liver function, liver lipid accumulation and liver lipid synthesis were determined through liver tissue morphological examination, blood biochemical examination, and detection of hepatic gene and protein expression.The results showed that lipid droplets in liver of mdx mice increased significantly.The contents of total cholesterol and triglyceride in liver, aspartate aminotransferase and alanine aminotransferase in serum increased.The gene and protein expression of hepatic lipid synthesis-related enzymes such as fatty acid synthase, acetyl CoA carboxylase, and sterol regulatory element binding protein 1-c were up-regulated.These results showed accumulation of liver lipid in 7-week-old mdx male mice.