Pichia pastoris displaying ZIKV protein epitopes from the Envelope and NS1 induce in vitro immune activation

• Published in: Vaccine 2021-04, Vol.39 (18), p.2545-2554
• Main Authors: Silva, Anna Jéssica D., Jesus, André Luiz S., Leal, Lígia Rosa S., Silva, Guilherme Antonio S., Melo, Cristiane Moutinho L., Freitas, Antonio C.
• Format: Article
• Language: English
• Subjects: Antigens; Cassettes; CD16 antigen; CD4 antigen; CD8 antigen; Cell activation; Cell surface; Cell walls; Cloning; Cold; Cytokines; Enzymes; Epitopes; Genomes; Immune response; Immune system; Immunization; Immunofluorescence; Immunogenicity; Immunology; Immunostimulation; Interleukin 10; Interleukin 6; Kinases; Lymphocytes; Monocytes; Phenols; Pichia pastoris; Plasmids; Proteins; Spleen; Tropical diseases; Tumor necrosis factor-α; Vaccines; Viruses; Whole-cell vaccines; Yeast; Yeast surface display; Yeasts; ZIKV
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2021.03.065

•Vaccine strategy against ZIKV using the yeast P. pastoris.•Presentation of ZIKV epitopes on the surface of P. pastoris yeast cells.•Recombinant yeasts displaying ZIKV epitopes stimulated the production of Th1 cytokines in vitro. The severe consequences of ZIKV infection and its emergence and re-emergence in several countries have boosted vaccines' development. Yeasts such as Pichia pastoris has been widely employed as antigen carriers for immunization against infectious agents. Components of the yeast cell wall have immunostimulatory properties, and recombinant antigens can be anchored to the cell surface to enhance the presentation to the immune system. Here we aimed at producing and anchoring ZIKV proteins in the P. pastoris surface as a vaccine approach. Expression cassettes were designed with epitopes of the Envelope and NS1 proteins. Immunofluorescence microscopy confirmed the anchoring of recombinant proteins. Yeasts' ability to stimulate immune cells was evaluated in vitro by incubation with lymphocytes and monocytes isolated from mouse spleen. P. pastoris expressing EnvNS1 epitopes promoted increased levels of IL-6, IL-10, and TNF-α cytokines and an increase in the number of CD4+, CD8+, and CD16+ lymphocytes, similarly to ZIKV. This profile is indicative of the activation of immunological cells and suggests an immunogenic potential of the proposed yeast vaccines against ZIKV, reinforcing the possibility of P. pastoris as adjuvant and carrier of antigens.