A bacterium-like particle vaccine displaying Zika virus prM-E induces
systemic immune responses in mice
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 for vaccines. In this article,
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-△
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, forming ZI-△-PA-GEM. Moreover, when BALB/c
mice were immunized intramuscularly with ZI-△-PA-GEM combined with 201
VG and poly(I:C) adjuvants, durable ZIKV-specific IgG and protective
neutralizing antibody responses were induced. Potent B cell/DC
activation was also be stimulated early after immunization. Remarkably,
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.