Researchers have found new information about how chronic Hepatitis C virus (HCV) infection affects the immune system even after successful treatment. They discovered that regulatory T cells retain ‘epigenetic scars’ causing prolonged inflammation post-virus clearance.
Led by Director SHIN Eui-Cheol, researchers from the Institute for Basic Science (IBS) Korea Virus Research Institute’s (KVRI) Center for Viral Immunology provided insights into the lasting effects of chronic Hepatitis C virus (HCV) infection on the immune system even post successful treatment. They found that ‘epigenetic scars’ persist in regulatory T cells, maintaining inflammatory properties after the virus is eradicated from the body.
Hepatitis C is a severe disease caused by the Hepatitis C virus that can lead to liver cirrhosis and cancer. With the introduction of highly effective direct-acting antivirals (DAAs), the cure rates for chronic HCV have significantly improved. However, the immune system may not fully recover even after successful treatment.
The study focused on patients with chronic HCV who achieved sustained virologic response (SVR) after DAA treatment. SVR indicates the absence of the HCV virus in the blood 12 weeks post-treatment, showing successful virus elimination. The researchers observed that activated TREG cells remained high during and after treatment, suggesting sustained changes.
Further analysis through RNA sequencing and ATAC-seq revealed persistent alterations in the transcriptomic and epigenetic profiles of TREG cells post-virus eradication. Inflammatory markers like increased TNF signaling continued in these cells, indicating long-term immune changes caused by the virus. Even after clearance, these TREG cells still produced inflammatory cytokines, indicating lasting immune effects.
Monitoring of patients up to six years post-SVR showed ongoing inflammatory features. This underscores the need for continued observation of patients even after successful treatment to prevent long-term immune system issues and potential health complications.
Director SHIN Eui Cheol emphasized the importance of monitoring post-treatment to address persistent immune changes effectively and enhance the well-being of HCV patients.
The team is now studying the mechanisms behind the sustained inflammatory response in TREG cells to identify potential interventions that can reverse these immune changes.
Director Shin expressed interest in exploring if other chronic viral infections also lead to lasting immune alterations and aims to uncover the clinical implications of these findings.
The research findings were published in the Journal of Hepatology.
