Th17 and Treg cells function in SARS-CoV2 patients compared with healthy controls

Area of Science:

• Immunology
• Virology
• Pathophysiology

Background:

• Coronavirus disease 2019 (COVID-19) pathogenesis involves immune dysregulation.
• T helper 17 (Th17) and regulatory T (Treg) cells play critical roles in inflammation and immune balance.

Purpose of the Study:

• To investigate the differential responses of Th17 and Treg cells in COVID-19 patients.
• To correlate these immune cell responses with disease severity and outcomes.

Main Methods:

• Comparative analysis of 40 COVID-19 ICU patients and 40 healthy controls.
• Assessment of Th17 and Treg cell frequencies using flow cytometry.
• Measurement of gene expression (RORγt, FoxP3) and cytokine levels (IL-17, IL-23, TGF-β, IL-10) via real-time PCR and ELISA.

Main Results:

• COVID-19 patients exhibited significantly higher Th17 cell counts and associated factors (RORγt, IL-17, IL-23).
• Patients showed significantly lower Treg cell frequencies and associated factors (FoxP3, TGF-β, IL-10).
• Elevated Th17/Treg cell ratios, including RORγt/FoxP3 and IL-17/IL-10, were observed in patients, particularly those with fatal outcomes.

Conclusions:

• Enhanced Th17 and reduced Treg cell responses contribute to hyperinflammation, lung damage, and pathogenesis in COVID-19.
• The Th17/Treg cell ratio is a critical indicator of inflammation severity and mortality in COVID-19 patients.