Synthetic multi-epitope peptide vaccine against cross-reactive Zika viruses

Abstract

A synthetic peptide vaccine composition (ZV-MEV) consisting of a linear fusion of conserved Zika virus B-cell and T-cell epitopes selected by immunoinformatics with respect to antigenicity, MHC class I / II binding, non-toxicity, non-allergenicity and interferon-γ induction, wherein the epitopes are separated by protease-cleavable linkers and fused with a molecular adjuvant domain, formulated with a pharmaceutically acceptable carrier for prophylactic immunization.

Description

AREA OF INVENTION

[0001] The invention relates to peptide vaccine compositions and delivery systems comprising computer-selected B- and T-cell epitopes from the Zika virus polyprotein, fused with adjuvant domains and formulated with pharmaceutically acceptable excipients for prophylactic immunization against various strains. BACKGROUND OF THE INVENTION

[0002] The Zika virus (ZIKV) poses significant public health risks, including congenital Zika syndrome and neurological complications. Variability between different viral lineages complicates the development of a broad-spectrum vaccine, while safety concerns favor non-replicating platforms. Immunoinformatics enables the rapid, computer-aided prediction of conserved, immunogenic epitopes across different viral strains. Antigenicity, MHC binding, non-toxicity, and interferon-γ induction are investigated to develop multi-epitope constructs capable of promoting both humoral and cellular immunity. Peptide vaccines allow for the precise incorporation of protective determinants and the exclusion of reactogenic regions. The fusion of epitope chains with molecular adjuvants or the addition of external adjuvants and delivery systems (e.g.,TLR agonists, aluminum hydroxide, liposomes) enhance and prolong the immune response. Furthermore, docking constructs to innate receptors (e.g., TLRs) and immunosimulation allow for a more precise determination of the stability and immunogenic potential of the constructs prior to synthesis, thus shortening development times for variant-ready designs. SUMMARY OF THE INVENTION

[0003] The invention relates to ZV-MEV, a synthetic peptide multi-epitope vaccine comprising: a series of conserved B-cell epitopes and class I / II T-cell epitopes derived from the ZIKV polyprotein and filtered for antigenicity, non-toxicity, non-allergenicity, and interferon-γ induction; a molecular adjuvant fusion partner or an N / C-terminal adjuvant domain; and optional linkers to preserve epitope processing. The construct is formulated with a pharmaceutically acceptable carrier and, in certain embodiments, co-formulated with a TLR agonist or an aluminum hydroxide / liposome system to enhance immunogenicity. Structural modeling confirms stable secondary and tertiary structures; receptor docking (e.g.,(at TLR5 or other innate target structures) suggests favorable complex formation; and in silico immunosimulations predict robust antibody titers and polyfunctional T-cell responses across different ZIKV strains. DETAILED DESCRIPTION

[0004] The vaccine construct contains a linear fusion of several epitopes mapped from conserved regions of ZIKV envelope proteins (E), membrane proteins (prM / M), non-structural proteins (e.g., NS1, NS3, NS5), and other polyprotein segments. These epitopes were selected using immunoinformatics techniques (prediction of MHC-I / II binding and B-cell epitopes) and filtered by antigenicity assessment, toxicity and allergenicity testing, and IFN-γ epitope prediction to promote Th1-dominant immune responses. The epitopes are linked by protease-cleavable linkers (e.g., AAY, GPGPG) that ensure efficient antigen processing and MHC presentation while minimizing the formation of neo-epitopes at the junctions. A molecular adjuvant domain (e.g.,A flagellin-derived TLR5 agonist segment or alternative TLR-binding motifs is fused at the N- or C-terminus via a flexible linker to enhance innate activation. When using a TLR5 binding strategy, docking models predict stable interaction with the TLR5 ectodomain and acceptable binding energies. Physicochemical optimization considers net charge, hydrophobicity, and predicted solubility. Disulfide patterns and secondary structure susceptibility are evaluated to ensure manufacturability and stability in aqueous buffers. The formulated product contains the peptide construct in sterile buffer with stabilizers (e.g., trehalose), tonics, and, where specified, aluminum hydroxide adsorption or encapsulation in liposome / squalene-in-water emulsions to enhance depot effect and uptake by antigen-presenting cells.Quality attributes include peptide identity / purity (HPLC / MS), endotoxin control, aggregation profile, and consistent adjuvant content. The product is supplied in single-dose vials or pre-filled syringes; alternatively, a lyophilisate with reconstitution agent is available. Immunization regimens (e.g., prime boost) are supported by in silico immunosimulations demonstrating the induction of high-affinity antibodies against conformationally tolerant B-cell epitopes and CD4+ / CD8+ T-cell responses to conserved internal epitopes, predicting cross-lineage coverage. Variant flexibility arises from the epitope discovery pipeline: updated strain databases inform the re-evaluation of conserved epitopes; modular synthesis exchanges epitope building blocks while maintaining adjuvant / linker scaffolds, enabling rapid construct updates for emerging variants.Safety is ensured by excluding homologies to human proteins and known allergenic motifs. Predicted toxicity is minimized through computer-aided toxicoanalysis; the formulation's excipients meet pharmacopoeial standards for parenteral administration. Stability studies aim for a shelf life of several months at refrigerated temperatures; forced degradation provides information on protective excipients; the choice of container closure minimizes oxidation / hydrolysis. The platform can be extended to combination vaccines by adding epitope panels of related flaviviruses, carefully considering orthogonality to avoid immune interference.

Claims

[1] A synthetic peptide vaccine composition (ZV-MEV) consisting of a linear fusion of conserved Zika virus B-cell and T-cell epitopes selected by immunoinformatics with respect to antigenicity, MHC class I / II binding, non-toxicity, non-allergenicity and interferon-γ induction, wherein the epitopes are separated by protease-cleavable linkers and fused with a molecular adjuvant domain, formulated with a pharmaceutically acceptable carrier for prophylactic immunization. [2] Composition according to claim 1, wherein the molecular adjuvant domain comprises a TLR-agonistic sequence configured to enhance the activation of the innate immune system, and docking models indicate stable receptor binding; optionally, the composition further comprises an extrinsic adjuvant selected from aluminium hydroxide, liposomes or squalene emulsions to increase immunogenicity. [3] Composition according to claim 1 or 2, wherein the epitopes comprise conserved regions of Zika envelope, membrane and non-structural proteins to ensure cross-strain coverage, and in silico immunosimulations predict robust humoral and cellular responses with interferon-γ-predominant profiles. [4] A composition according to any of the preceding claims, which is in the form of a sterile solution or lyophilized powder with stabilizers, has a defined identity, purity and low endotoxin levels and is configured for rapid updates of the epitope set to combat newly emerging variants by means of modular synthesis.