PCV2 Regulates Cellular Inflammatory Responses through Dysregulating Cellular miRNA-mRNA Networks.

Area of Science:

• Virology
• Molecular Biology
• Immunology

Background:

• Porcine circovirus type 2 (PCV2) causes significant diseases in the global pig industry.
• PCV2 infection is associated with inflammation, as indicated by previous gene expression studies.
• MicroRNAs (miRNAs) are key regulators of cellular processes, including immune responses.

Purpose of the Study:

• To investigate the role of host and viral microRNAs (miRNAs) during Porcine circovirus type 2 (PCV2) infection.
• To explore the impact of PCV2 infection on miRNA expression profiles.
• To elucidate the mechanisms by which miRNAs modulate PCV2-induced inflammation.

Main Methods:

• Next-generation sequencing was used to analyze miRNA expression in PCV2-infected and non-infected PK-15 cells.
• Bioinformatic analysis identified known and novel differentially expressed miRNAs (DE miRNAs) and their target mRNAs.
• Functional assays (miRNA overexpression and down-expression) were performed to validate the role of specific miRNAs.

Main Results:

• PCV2 does not express its own miRNAs in vitro.
• 44 known and novel miRNAs were found to be differentially expressed between infected and non-infected cells.
• PCV2 infection perturbed inflammatory pathways, notably chemokine and cytokine signaling.
• A miRNA-mRNA interaction network demonstrated PCV2's regulation of cellular inflammation via miRNA dysregulation.

Conclusions:

• Host miRNAs are dysregulated by PCV2 infection.
• PCV2 manipulates the host miRNA-mRNA network to modulate cellular inflammatory responses.
• Host miRNAs play a critical role in the pathogenesis of PCV2-associated diseases.