Document Type
Thesis - Open Access
Award Date
2024
Degree Name
Master of Science (MS)
Department / School
Biology and Microbiology
First Advisor
Gergely Imre
Abstract
Programmed cell death (PCD) or in other terms regulated cell death refers to a controlled process of cellular self-destruction that occurs in multicellular organisms. Notable forms of regulated cell death include apoptosis, necroptosis, and pyroptosis, each driven by specific signaling pathways and molecular mechanisms. Notably, pathogenassociated molecular patterns (PAMPs) such as viral RNA, DNA and proteins could instigate host cell immune response and, in some circumstances, regulated cell death. A family of cysteine proteases termed caspases play a central role in the regulation of cell death known as apoptosis. In necroptosis, the activation of receptor-interacting kinases (RIPK) leads to the oligomerization of mixed lineage kinase domain-like pseudokinase (MLKL), which induces the formation of transmembrane pores, culminating in cellular disintegration. Lytic forms of regulated cell death remain underexplored in the context of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) infection, a devastating infectious disease in swine. In this study, we established a flow cytometry-based doublestaining method for the identification of infected and dying cells at a single-cell resolution. By leveraging this quantitative method, we demonstrated that PRRSV infection-induced cell death could not be inhibited by exclusively blocking apoptosis. This non-apoptotic cell death exhibited the activity of MLKL and increased membrane permeability/rupture, which are the characteristics of necroptosis. Additionally, pharmacological inhibition of MLKL significantly reduced PRRSV-induced cell death in infected MARC-145 cells and porcine alveolar macrophages. In conclusion, PRRSV induces both apoptotic and necroptotic cell death. Only the inhibition of both pathways results in a complete cell death inhibition. Reduction of macrophage cell death and tissue destruction in PRRSV infection has the potential to significantly increase the survival rate of the infected animals.
Publisher
South Dakota State University
Recommended Citation
Steyn, Michelle, "Investigating the Role and Mechanism of Host Cell Death in Porcine Reproductive and Respiratory Virus Infection" (2024). Electronic Theses and Dissertations. 965.
https://openprairie.sdstate.edu/etd2/965
Rights Statement
