Qiu Xu, Wei Zhou, Shihao Ding, Yao Lu, Songyan Liu, Jun Cao, Zhuo Zhang, Siguo Liu, Shenye Yu

Res Vet Sci.2021 Nov 2;141:180-189.doi: 10.1016/j.rvsc.2021.10.019. Online ahead of print.

Abstract

Johne's disease, or paratuberculosis, is a chronic granulomatous enteritis of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). This disease occurs worldwide and results in considerable economic losses in the livestock industry. There are no effective treatments for Johne's disease, so there is an urgent need to develop an efficient, economical, and stable vaccine for MAP control. Here, a live Escherichia coli (E. coli) surface display vaccine harboring the MAP3061c gene was developed through an ice nucleation protein (INP) surface display system. The experimental data demonstrated that MAP3061c has strong immunogenicity and that the surface displayed vaccine can stimulate mice to produce high levels of antibodies. Both CD4+ and CD8+ T cell counts as well as several cytokines - including IFN-γ, IL-4, IL-10, IL-17A and IL-23 - were significantly increased in the display vaccine group. Post-vaccination challenge with MAP in mice resulted in improved fitness of the mice as demonstrated by a lack of weight loss. Pathological results revealed that the surface display vaccine could reduce the degree of pathological damage and slowed the course of disease. Taken together, our data suggests that the E. coli carrier vaccine with surface-displayed MAP3061c elicits protective immunity against MAP, providing new insights into the development of a MAP vaccine.

Keywords: Carrier vaccine; Immune protection; MAP3061c protein; Mycobacterium avium subsp. paratuberculosis; Surface display.

Copyright © 2021. Published by Elsevier Ltd.