[Expression of alpha-defensin-1 with J chain in the transfected COS-7 cells].

Objective: To recombine the alpha-defensin-1 (HNP-1) and J chain cDNA fragment into a new germicidal molecule J-HNP-1, and investigate its expression in the transfected COS-7 cells.

Methods: J chain and HNP-1 cDNA were amplified from the plasmids pCH-J and pBabeNeo-HNP-1 respectively, then the J-HNP-1 DNA fragment was obtained by recombinant polymerase chain reaction (PCR). The J-HNP-1 fragments were inserted into pcDNA3.1 (-)/Myc-HisC, which subsequently was made to transfect the COS-7 cell by lipid transfection method. The expression was confirmed by Western blot.

Results: Determination with His antibody, a dense band at 24 ku was displayed by the cell lysate and the cell culture supernatant in concordance with that of the predicted extent, but not in the control.

Conclusion: The new germicidal peptide J-HNP-1 is found to be expressed intracellularly and could be secreted. The results lay the foundation for further study on the germicidal activity of J-HNP-1.