Objective: To investigate the feasibility to transfect human beta defensin 2 (hBD2) gene into the lung so as to enhance the endogenous hBD2 expression to defend infectious diseases.
Methods: Recombinant plasmid containing hBD2 gene, pLXSN-hBD2, was mixed with a new cationic liposome prepared by film at different weight ratios. Sixteen Wistar rats were divided into 2 groups: experimental group (n = 11), undergoing aerosol inhalation of liposome/pLXSN-hBD2 complex, and control group (n = 5), undergoing aerosol inhalation of blank vector pLXSN. The tracheae were taken out from 5 rats of the experiment and control groups each 2 days later, and from 2 rats of the experimental group 6, 15, and 21 days later respectively so as to obtain the epithelial cells of trachea. DNA was extracted from the tracheal epithelial cells and PCR was used to examine the transfection and integration of hBD2. Western blotting was used to detect the protein expression of hBD2.
Results: Aerosolization impacted obviously the microcapsule structure of liposome/plasmid complexes, and there was the least structural destruction of complex at a ratio of 10:1 that suited for aerosolization best. After the inhalation the relevant plasmids were all successfully integrated into the epithelial cells in both groups. Protein expression of hBD2 was not detected in the control group and the hBD2 protein expression level 2 days after transfection of the experimental group was 4866.9 +/- 148.2, and then decreased gradually, and reached 3.2 +/- 1.5 twenty-one days after the transfection.
Conclusion: The recombinant plasmid pLXSN-hBD2 can be transfect into the airway epithelial cells via aerosol inhalation and the expression of hBD2 sustains for a period of time.