Development and immunogenicity evaluation of attenuated Salmonella typhimurium delivering porcine Deltacoronavirus S1 gene

Junpeng Yang; Rui Chen; Mengke Sun; Rong Yuan; Ying Feng Xiao; Ying Sun; Guiping Zhou; Yiping Wen; Yiping Wang; Rui Wu; Qin Zhao; Senyan Du; Sanjie Cao; Xiaobo Huang

doi:10.1016/j.ijbiomac.2024.138615

Development and immunogenicity evaluation of attenuated Salmonella typhimurium delivering porcine Deltacoronavirus S1 gene

Int J Biol Macromol. 2024 Dec 12:288:138615. doi: 10.1016/j.ijbiomac.2024.138615. Online ahead of print.

Authors

Junpeng Yang¹, Rui Chen¹, Mengke Sun¹, Rong Yuan², Ying Feng Xiao², Ying Sun¹, Guiping Zhou¹, Yiping Wen¹, Yiping Wang¹, Rui Wu¹, Qin Zhao¹, Senyan Du¹, Sanjie Cao³, Xiaobo Huang⁴

Affiliations

¹ Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
² Chengdu Livestork and Poultry Genetic Resources Protection Center, China.
³ Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu 611130, China; National Animal Experiments Teaching Demonstration Center, Sichuan Agricultural University, Chengdu 611130, China; International joint Research Center for Animal Disease Prevention and control of Sichuan Province, Chengdu 611130, China.
⁴ Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu 611130, China; National Animal Experiments Teaching Demonstration Center, Sichuan Agricultural University, Chengdu 611130, China; International joint Research Center for Animal Disease Prevention and control of Sichuan Province, Chengdu 611130, China. Electronic address: rsghb110@126.com.

PMID: 39674474
DOI: 10.1016/j.ijbiomac.2024.138615

Abstract

Porcine deltacoronavirus (PDCoV) is a swine enteropathogenic coronavirus that causes severe diarrhea in piglets, the development of novel vaccines is of great value in the prevention and control of PDCoV. Here, we selected attenuated Salmonella typhimurium SL7207 to deliver pVAX1-S1, resulting in the oral vaccine strain, SL7207 (pVAX1-S1). In immunized mice, SL7207 (pVAX1-S1) induced PDCoV-specific humoral IgG, IgA, neutralizing antibodies, mucosal sIgA, up-regulation of CD8⁺ T cells, and increased levels of Th1 cytokines (IFN-γ and IL-2). In piglets, SL7207 (pVAX1-S1) induced high levels of PDCoV-specific humoral IgG and neutralizing antibodies but no detectable IgA, and only low levels of mucosal sIgA. SL7207 (pVAX1-S1) also promoted T cell differentiation into CD4⁺ and CD8⁺ T cells, and increased the expression level of IFN-γ and IL-4 in peripheral blood. Challenge experiments in piglets showed SL7207 (pVAX1-S1) alleviated diarrhea, decreased fecal virus load and intestinal lesions compared with control groups. In conclusion, this study systematically evaluated the immunogenicity and feasibility of attenuated Salmonella typhimurium delivering PDCoV S1 gene, which will provide helpful reference information for further exploration of novel PDCoV oral vaccine.

Keywords: Attenuated Salmonella typhimurium; Oral immunization; Porcine deltacoronavirus S1 gene.