Circulating PD-1^hiCXCR5⁺CD4⁺ T cells are associated with a decrease in hepatitis B surface antigen levels in patients...

Area of Science:

• Immunology
• Hepatology
• Virology

Background:

• Follicular T helper (Tfh) and peripheral T helper (Tph) cells play crucial roles in adaptive immunity.
• Chronic hepatitis B (CHB) is a significant global health concern characterized by persistent HBV infection.
• Understanding T cell subsets involved in CHB pathogenesis is vital for developing effective therapies.

Purpose of the Study:

• To investigate the roles of circulating PD-1hiCXCR5+CD4+ T cells and PD-1hiCXCR5-CD4+ T cells in CHB.
• To assess the association of these T cell populations with hepatitis B surface antigen (HBsAg) reduction and HBV clearance.
• To evaluate the impact of peginterferon-α (PEG-IFN-α) therapy on these T cell subsets and their relation to treatment outcomes.

Main Methods:

• Flow cytometry was used to quantify the frequencies of PD-1hiCXCR5+CD4+ T cells and PD-1hiCXCR5-CD4+ T cells.
• A longitudinal study design was employed, including measurements before and after 48 weeks of PEG-IFN-α therapy.
• Serum HBsAg levels and HBV DNA concentrations were repeatedly measured to assess treatment response.

Main Results:

• Frequencies of both PD-1hiCXCR5+CD4+ and PD-1hiCXCR5-CD4+ T cells were significantly higher in CHB patients than in healthy controls.
• An increase in PD-1hiCXCR5+CD4+ T cell frequency post-PEG-IFN-α treatment was significantly associated with lower HBsAg levels.
• No significant differences in HBsAg levels or HBV DNA clearance were observed concerning PD-1hiCXCR5-CD4+ T cell frequency changes.

Conclusions:

• Circulating PD-1hiCXCR5+CD4+ T cells are associated with reduced HBsAg levels in CHB patients receiving PEG-IFN-α therapy.
• Both PD-1hiCXCR5+CD4+ and PD-1hiCXCR5-CD4+ T cells may be involved in the immune landscape of chronic HBV infection.
• Further research is warranted to elucidate the precise mechanisms and therapeutic potential of these T cell subsets in CHB.