Production of Recombinant Protein of Salsola Kali (Sal k1) Pollen Allergen in Lactococcus Lactis

The Salsola kali pollen is considered the main cause of allergic sensitization in desert and semi-desert regions. We have constructed recombinant Lactococcus lactis producing Sal k1 protein with the aim of using it as a mucosal vaccine for specific immunotherapy. The Sal k1 gene was amplified, and transferred into a PNZ 8148 plasmid. The PNZ8148-Sal k1 recombinant plasmid was transformed into competent E.coli strain MC1061 for replication, and then was isolated and cloned into competent L. lactis by electroporation. The cloning was verified by PCR and gene sequencing. The production of recombinant Sal K1 (rSal K1) protein was induced by nisin. The rSal K1 protein was purified by affinity chromatography and dialysis, and confirmed by SDS-PAGE and western blot analyses. The recombinant L. lactis was successfully constructed. Production of a 40-kDa rSal k1 protein with the L. lactis was shown by sodium dodecyl sulfate-polyacrylamid gel electrophoresis (SDS-PAGE) analysis. In addition, western blot analysis using specific mouse anti-Sal k1 polyclonal antibodies and sensitive human sera verified the 40-kD protein as rSal k1 allergen. This study demonstrated that L. lactis may be used as a promising live delivery system for recombinant Sal k1 protein without altering its immunoreactivity; however, its efficacy in the context of the immune system is suggested to be pursued in future studies.