DEVELOPMENT OF A VACCINE CANDIDATE BASED ON VIRUS-LIKE PARTICLES AND AN IMMUNO-STIMULANT ADJUVANT AGAINST ZIKA VIRUS CAPABLE OF INDUCING A STRONG MUCOSAL RESPONSE

LUCIANA A. FASSOLA; GUILLERMO ALBRIEU-LLINÁS; FELICITAS ANTONINO; LUCIA L. RUPIL; DAMIÁN O. PERALTA; MARIANELA C. SERRADELL

San Luis capital

Congreso; LXXI Reunión Científica Anual de la Sociedad Argentina de Inmunología SAI; 2023

SOCIEDAD ARGENTINA DE INMUNOLOGÍA (SAI)

Virus-like particles (VLPs) are a type of subunit vaccines that possess diverseapplications in therapeutics, immunization, and diagnostics. On one hand, VLPbased vaccines are being extensively used because of their efficacy, safety anddiversity. On the other hand, Giardia lamblia variable surface proteins (VSPs)have been shown to act as adjuvants and endure extreme conditions. Theseprotozoan proteins can be used to generate oral vaccines due to their outstandingresistance to proteases and to changes in pH, immunogenicity and absence oftoxicity. Previously, using an Influenza viral model, it was shown that surfacedecorated VLPs with VSPs triggered a successful immune response after oraland subcutaneous immunization with hemagglutinin glycoprotein. Consideringthe increasing global impact of arboviruses, our goal is to develop a safe andeffective vaccine against Zika virus (ZIKV, Flavivirus) using VLP-VSP inconjunction with specific viral antigens. ZIKV infection causes an acute febriledisease including rash, conjunctivitis and arthralgia, and it is also associated withcomplications such as Guillain-Barré syndrome and complex congenitaldisorders. So far, there are no available vaccines against ZIKV, which is spreadnot only by hematophagous mosquitoes but also sexually among humans. In thiscontext, for an optimal Zika vaccine, ensuring safety is of utmost importance,particularly when considering its administration to pregnant women. Additionally,the vaccine should elicit a robust mucosal response to effectively counteractsexual transmission. In this sense, the VLP-VSPs platform fulfills the safetycriteria owing to the absence of viral genome and its adaptability foradministration through various routes. At the outset, we amplified and insertedthe gene encoding the ZIKV-E into a mammalian vector (pEZIKV). We thenverified its accurate expression in different cell lines through immunofluorescenceobservation. For the production of VLPs, we co-transfected HEK cells thatconstitutively express a specific r Giardia VSP (VSP1267) with two plasmids: oneencoding the Murine Leukemia Virus capsid, promoting the subsequent selfassembly of the VLPs (pMLV-Gag) and pEZIKV. This approach led to thesuccessful expression of the ZIKV E glycoprotein in VLP-VSP constructs. Theproper assembly was confirmed by Western blotting and transmission electronmicroscopy (TEM), using anti-Zika E antibodies. Finally, we assessed theimmune response in Balb/c mice by administering VLP-VSP-EZIKV through bothoral and subcutaneous routes. The presence of anti-ZIKV antibodies, confirmedby ELISA, verified the humoral response in both serum and mucosal samples.Additionally, ongoing analysis of the cytokine profile is underway. The data wereanalyzed by one-way ANOVA followed by Tukey’s multiple comparison test. Our findings demonstrate the capacity to produce targeted antibodies using a securevaccine that can accommodate various administration protocols.