Performing Department
(N/A)
Non Technical Summary
Senecavirus A (SVA) has recently emerged in several of the major swine producing countries worldwide, causing VD outbreaks in swine that are clinically indistinguishable from FMD and other high consequence FADs of livestock. Notably, since the emergence of the virus in the US in 2015 over 3000 outbreaks of SVA-induced VD have been confirmed. Vesicular diseases are among the most important diseases of livestock. The annual cost of FMD, for example, has been estimated to amount between $6.5 and $21 billion per year in endemic regions, whereas FMD outbreaks in disease free countries (like the US) could cost up to $84 billion. The similarity of SVA with such high consequence FADs and the fact that the virus is capable of establishing persistence and a carrier state in infected animals which transmit the virus to other susceptible animalshighlight the significance of the disease. Understanding the mechanisms underlying establishment and maintenance of SVA persistence is critical to implement effective prevention and control measures to mitigate the impact that circulation of the virus causes to the US livestock industry.The main goals of the study proposed here are to elucidate the mechanisms and host cell functions exploited by SVA during persistence as well as to identify viral determinants underlying SVA's ability to establish and maintain long-term persistent infections.The outcomes of this study will significantly improve our understanding of SVA infection biology and persistence and are likely to shed light on the pathways and molecular mechanisms that may have enabled the maintenance and transmission of the virus in the swine population for the last three decades.A direct application of the basic knowledge generated here through the identification of molecular determinants of SVA persistence could lead to the development of safer and highly efficient vaccines devoid of their ability to establish persistence.
Animal Health Component
100%
Research Effort Categories
Basic
60%
Applied
30%
Developmental
10%
Goals / Objectives
Senecavirus A (SVA) is an emerging picornavirus of swine that causes foot-and-mouth- (FMD)-like vesicular disease (VD) in affected animals and is known to establish persistent infections in pigs. Most importantly, carrier animals can serve as source of infection to other susceptible pigs. Currently, however, little is known about the mechanisms underlying SVA persistence. In the present project we will test the hypothesis that modulation of host survival and antiviral pathways by SNA determines the fate of infected cells, which cycle between lytic and persistent infection. We propose to dissect the mechanisms underlying SVA persistence using in vivo and in vitro and model systems of persistent infection. The objectives of this study are:To define virus-host cell interactions underlying establishment and maintenance of persistent SVA infection in vivo.To characterize molecular determinants of SVA persistence.These objectives are related to the program area of Diseases of Agricultural Animals (A1221). The work is directly aligned with the priority areas of "Cellular aspects of animal health, maintenance and homeostasis" and the sub priority area of "disease prevention and control". The work proposed here will significantly contribute to the improvement and sustainability of the US livestock industry by generating foundational knowledge regarding SVA persistence in swine. Such knowledge may be translated to safe live attenuated SVA vaccines and to improved strategies for prevention and control of SVA and other highly relevant VDs of swine.
Project Methods
The overall goal of the proposed study is to dissect the mechanisms underlying establishment and maintenance of SVA persistence in the swine host. To achieve this goal we proposed two objectives and a series of experimental studies as outlines below:Aim 1: To define virus-host cell interactions underlying establishment and maintenance of persistent SVA infection. In Aim 1 we propose: (ii) to determine the host cell responses at different stages of infection (acute, transitional and persistence) in the tonsil in vivo (Aim 1.1); and (ii) to dissect the role and function of host factors modulated during persistence on SVA life cycle and on its ability to establish and maintain persistence (Aim 1.2). For this, we will use cutting edge single-cell RNA sequencing (scRNA-seq) coupled with spatial transcriptomics (ST) to unveil SVA host cell interactions as they take place during establishment and maintenance of the persistent infection in the tonsil in vivo. Additionally, porcine tonsillar cell culture libraries stably expressing- or containing CRISPR/Cas9 gene knockouts will be used to dissect the function of identified host factors on SVA infection, replication and persistence.Aim 2: To identify and characterize molecular determinants of SVA persistence. In Aim 2 we plan to identify viral determinants of persistence and characterize their role on SVA persistence. Mutations that we identified in specific SVA proteins during persistence will provide the foundation for these studies. They will be coupled with our SVA reverse genetics system to determine their contribution to virus persistence using in vitro and in vivo model systems.