Preventive effect of DNA vaccine based on xenogeneic homologous calcium-activated chloride channel on airway hyperresponsiveness in asthmatic mice

AIM: To observe the preventive effect of DNA vaccine based on human calcium-activated chloride channel 1 (hCLCA1) on airway hyperresponsiveness in asthmatic mice.METHODS: The DNA vaccine was constructed by inserting the hCLCA1 gene into pSecTag-2A, and then BALB/c mice were vaccinated by im. once every two weeks. Serum antibody was checked with the antigen of mCLCA3 by ELISA analysis. Asthma was induced with ovalbumin in the vaccinated mice. The airway pressure time index (APTI), the contractile responsiveness of isolated tracheal rings and the number of eosinophil in bronchoalveolar lavage (BAL) were investigated. Mice injected with pSecTag-2A, saline or normal mice were regarded as control groups. RESULTS: The title of antiserum binding to mCLCA3 in vaccine group was 1∶800 to 1∶1 000 after three times vaccination. Compared with normal group, APTI, contractile responsiveness and number of eosinophil in vaccine group, pSecTag-2A or saline group were increased markedly (P<0.01). These indexes in vaccine group were obviously lower than those in pSecTag-2A and saline groups (P<0.01). The latter two groups had the similar results. CONCLUSION: hCLCA1 DNA vaccine induces mouse to produce serum antibody binding to itself mCLCA3, and thus airway hyperresponsiveness and aggregation of eosinophil in asthmatic mouse are effectively inhibited.