Transcriptome profiling analysis of grouper during nervous necrosis virus persistent infection

Area of Science:

• Aquaculture
• Fish immunology
• Virology

Background:

• Nervous necrosis virus (NNV) causes significant losses in farmed grouper aquaculture.
• Persistent NNV infection creates carriers, complicating disease control through viral shedding via spawning.

Purpose of the Study:

• To investigate transcriptomic changes in grouper brain tissue during NNV persistent infection.
• To understand the molecular mechanisms underlying impaired NNV clearance in carrier grouper.

Main Methods:

• RNA-sequencing (RNA-Seq) was employed to profile gene expression.
• Gene expression was analyzed in brain tissue from persistently infected grouper, with an inactivated-NNV vaccine group as a control.

Main Results:

• Persistent NNV infection activated immune cell signaling and surface receptor expression.
• Interferon-induced responses were significantly upregulated in infected brain tissue.
• Key negative regulators of T-cells, including PD-L1 and LAG3, were found to be upregulated.

Conclusions:

• The study provides a comprehensive transcriptomic view of NNV persistent infection in grouper.
• Upregulation of negative T-cell regulators suggests a mechanism for impaired viral clearance.
• Findings offer insights into managing NNV carrier states in aquaculture.