Transient Interferon-Driven Natural Killer Cell Activation in Acute Hepatitis C.

Area of Science:

• Immunology
• Virology
• Transcriptomics

Background:

• Acute hepatitis C virus (HCV) infection is rare but treatable with direct-acting antivirals (DAAs).
• Natural Killer (NK) cells are crucial in the immune response during acute HCV infection.

Purpose of the Study:

• To investigate the role and characteristics of NK cells during acute HCV infection.
• To compare NK cell profiles in acute HCV, chronic HCV, and healthy individuals.
• To analyze transcriptomic changes in NK cells during acute HCV infection and after DAA treatment.

Main Methods:

• Longitudinal sampling of patients with acute HCV.
• Flow cytometry and single-cell sequencing for NK cell analysis.
• Transcriptomic analysis to identify cellular pathways.

Main Results:

• A distinct subset of highly activated NK cells with a type-I interferon signature was identified in acute HCV.
• This activated NK cell population diminished after successful DAA therapy.
• A long-term phenotypic alteration in NK cells was observed post-cure compared to healthy controls.

Conclusions:

• Interferon drives an increase in activated NK cells during acute HCV infection.
• Viral clearance via DAAs largely restores NK cell populations, but a residual imprint persists.
• These findings illuminate the immunological underpinnings of effective antiviral responses in hepatitis C.