Serum Interleukin-35 Level in Correlation with T Regulatory and T helper-17 Cells Frequency in Chronic Viral Hepatitis C Patients

• Main Authors: Safaa S. Abo-Elnour, Amira E. Abdelhamid, Sherine E. Bendary, Ossama A. Ahmed, Heba I. Aly, Dina M. Erfan
• Format: Article
• Language: English
• Published: Journal of Pure and Applied Microbiology 2020-12-01
• Series: Journal of Pure and Applied Microbiology
• Subjects: hcv; chc; interleukin 35; immunosuppressive cytokines; t helper 17 cells; t regulatory cells
• Online Access: https://microbiologyjournal.org/serum-interleukin-35-level-in-correlation-with-t-regulatory-and-t-helper-17-cells-frequency-in-chronic-viral-hepatitis-c-patients/

Interleukin-35 (IL-35), secreted mainly by T-regulatory cells (T-regs), has been considered to have immunosuppressive actions in many auto-immune diseases and tumors. However, information about its role in chronic hepatitis C (CHC) infection is still limited. We aimed to study the role of IL-35 within CHC infection and to assess its correlation with T-regs and T-helper 17 cells (Th-17). Therefore, we measured serum IL-35 concentrations using ELISA assay in 25 normal controls (NCs) and in 30 CHC patients before receiving direct antiviral agents (DAA) treatment and after 3 months of treatment end. T-regs and Th-17 cells frequencies were assessed via flow-cytometry in control group and patients’ group before treatment. The results showed that serum IL-35 levels revealed a highly significant increase in CHC patients compared to NCs (P <0.001). Moreover, IL-35 levels significantly decreased in patients 3 months after treatment end (P =0.02). Both Th-17 and T-regs were significantly increased in patients more than in NCs and a positive correlation was observed between them. However, T-regs/Th-17 ratio did not show significant difference from the ratio in NCs. IL-35 levels were positively correlated with viral load and T-regs frequency, but not with Th-17 frequency. IL-35 levels did not correlate with liver enzymes or functions. These results suggested that IL-35 enhances the immunosuppressive functions of T-regs, protecting the liver from HCV induced damage and contributes to viral persistence. IL-35 may represent a possible immunotherapeutic strategy for chronic persistent infection if given with DAA, especially in relapsing or non-responding cases.