Document Type

Thesis - Open Access

Award Date

2024

Degree Name

Master of Science (MS)

Department / School

Biology and Microbiology

First Advisor

Xiuqing Wang

Abstract

Porcine reproductive and respiratory syndrome virus (PRRSV) is an enveloped, positive-sense, single-stranded RNA virus from the Arteriviridae family. PRRSV causes respiratory illness and reproductive failure in infected pigs. Outbreaks occurring in the United States and worldwide cause significant economic losses annually. Abelson (Abl) tyrosine kinase is a non-receptor tyrosine kinase, which plays a central role in regulating many cellular processes such as actin reorganization, cell proliferation and differentiation by transducing extracellular and intracellular signals. Abl inhibitors have been shown to restrict the entry of membrane fusion of enveloped viruses, such as severe acute respiratory syndrome coronavirus, Middle Eastern respiratory syndrome virus, infectious bronchitis virus and others, to reduce virus replication. The objective of this study is to investigate the role of Abelson inhibitors against PRRSV replication. To achieve this, we pre-treated MARC-145 cells with varying concentrations of an Abl kinase inhibitor, imatinib, followed by a second treatment and an infection with PRRSV. To determine infection rates, the cells were stained with a FITC-labeled monoclonal antibody against PRRSV nucleocapsid protein (FITC-SDOW17) and quantified with flow cytometry. Further confirmation was performed with immunofluorescence staining, microscopy, and TCID50 assays. Cells treated with imatinib show a reduction in virus positive cells as compared to the untreated controls groups. These differences were further observed with both microscopy and TCID50 assays, with a dose-dependent reduction in viral titers and number of virus positive cells as the concentration of the imatinib increased. This indicates that the Abl kinases that imatinib block in MARC-145 cells participate in viral replication. Additionally, to determine if the imatinib had any cytotoxic effect on the cells, a cytotoxicity assay was performed, and it was determined that imatinib at concentrations of 40 μM and 50 μM has a toxic effect on the cells. In summary, our data suggests that Abl kinase mediated signaling pathways play a role in PRRS replication and by blocking them viral infection can be reduced. However, this comes at the cost of cell viability. Future studies will investigate the mechanism by which Abl kinase inhibitors reduce PRRSV replication in vitro.

Publisher

South Dakota State University

Download

Share

COinS
 

Rights Statement

In Copyright