Bacteriophage Q virus-like particles displaying Chikungunya virus B-cell epitopes elicit high-titer E2 protein antibodies but fail to neutralize a Thailand strain of Chikungunya virus

Chikungunya virus (CHIKV) is a mosquito-borne virus associated with arthritis and musculoskeletal pains. More than 2.9 million people worldwide have been infected with the virus within the last 1.5 decades; currently, there are no approved vaccines to protect against CHIKV infection. To assess the potential of using CHIKV peptides as vaccine antigens, we multivalently displayed CHIKV peptides representing B-cell epitopes (amino acids 2800-2818, 3025-3058, 3073-3081, 3121-3146, and 3177-3210), from E2 glycoprotein (Singapore strain), on the surface of a highly immunogenic bacteriophage Q beta virus-like particle (VLP). We assessed the immunogenicity of CHIKV E2 amino acid 3025-3058 (including the other epitopes) displayed on Q beta VLPs in comparison to the same peptide not displayed on VLPs. Mice immunized with the E2 peptides displayed on Q beta VLPs elicited high-titer antibodies compared with the group immunized just with the peptide. However, sera from immunized mice did not neutralize CHIKV AF15561 (isolated from Thailand). The data suggest that Q beta VLPs is an excellent approach to elicit high-titer CHIKV E2-protein antibodies at a lower dose of antigen and future studies should assess whether Q beta-CHIKV E2 aa 2800-2818 VLPs and Q beta-CHIKV E2 aa 3025-3058 VLPs can neutralize a Singapore Strain of CHIKV. (C) 2020 Elsevier Ltd. All rights reserved.