Humoral and cellular immunity in mice immunized with whole recombinant yeast expressing complex NS2B/NS3 protein of dengue serotype

A nonpathogenic edible yeast, Saccharomyces cerevisiae, has been identified as a vehicle to express many foreign antigens which elicit the immune response in mice. The complex NS2B/NS3 is a protease that represents a prime target for rational drug design for dengue infection. During infection, the NS3 protein is the main target for CD4+ and CD8+ T cell responses, which may be protective. However, no studies have been undertaken evaluating the use of recombinant yeast Saccharomyces cerevisiae INVSc1 expressing complex NSB/NS3 protease as a protective antigen against dengue infection. In the present study, we evaluated the humoral and cellular immune response elicited by recombinant yeast compared to wild-type yeast in the mouse model. Intraperitoneal (i.p.) administration of recombinant and wild-type yeast at 1 and 25 yeast units into BALB/c mice was used. These studies demonstrated that administration at a low concentration of recombinant yeast at 1 yeast units (YU) significantly elicits antibodies against DENV NS3 antigen. Furthermore, real-time PCR analysis revealed that NS2B/NS3-specific cytocines (TNF-α, IFN-, IL-2) increased with moderate mode compared to wild-type yeast. The results in this study show the potential of recombinant yeast as an edible vaccine platform against dengue infection.