A bacterium-like particle vaccine displaying Zika virus prM-E induces systemic immune responses in mice

Transbound Emerg Dis. 2022 May 11. doi: 10.1111/tbed.14594. Online ahead of print.

Abstract

The emergence of Zika virus (ZIKV) infection, which is unexpectedly associated with congenital defects, has prompted the development of safe and effective vaccines. The gram-positive enhancer matrix-protein anchor (GEM-PA) display system has emerged as a versatile and highly effective platform for delivering target proteins in vaccines. In this study, we developed a bacterium-like particle vaccine, ZI-△-PA-GEM, based on the GEM-PA system. The fusion protein ZI-△-PA, which contains the prM-E-△TM protein of ZIKV (with a stem-transmembrane region deletion) and the protein anchor PA3, was expressed. The fusion protein was successfully displayed on the GEM surface to form ZI-△-PA-GEM. Moreover, the intramuscular immunization of BALB/c mice with ZI-△-PA-GEM combined with ISA 201 VG and poly(I:C) adjuvants induced durable ZIKV-specific IgG and protective neutralizing antibody responses. Potent B-cell/DC activation was also stimulated early after immunization. Notable, splenocyte proliferation, the secretion of multiple cytokines, T/B-cell activation and central memory T-cell responses were elicited. These data indicate that ZI-△-PA-GEM is a promising bacterium-like particle vaccine candidate for ZIKV. This article is protected by copyright. All rights reserved.

Keywords: GEM; ZIKV; bacterium-like particle; prM-E protein.