Defining the Role of Th17 Lineage Cells in People with COVID-19


  • Sarah Connolly Human and Translational Immunology Group, School of Medicine, Trinity College Dublin, The University of Dublin, Ireland; Trinity Translational Medicine Institute, Trinity Centre for Health Sciences, St. James's Hospital, Dublin, Ireland
  • Sharee A. Basdeo Human and Translational Immunology Group, School of Medicine, Trinity College Dublin, The University of Dublin, Ireland; Trinity Translational Medicine Institute, Trinity Centre for Health Sciences, St. James's Hospital, Dublin, Ireland


Th17 Cells, COVID-19, SARS-CoV-2


Coronavirus disease 2019 (COVID-19) is a pandemic disease which has created a serious public health threat worldwide and causes pneumonia due to infection of the host with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). There remains a key gap in the understanding of what decides the outcome between an appropriate immune response and immunopathology in COVID-19. Th17 lineage cells are a distinct population of CD4+ T helper cells which mediate protection against bacteria and fungi. Th17 cells are dysregulated in patients with severe COVID-19 and are significant contributors to the systemic cytokine storm experienced by critical patients. Th17 cells have been described to mediate damage in the lungs of COVID-19 patients by encouraging the recruitment of neutrophils, contributing to acute respiratory distress syndrome and cytokine storms, causing pulmonary fibrosis, disrupting normal alveolar architecture and oxygenation processes and ultimately leading to systemic organ damage and death. Th17 cells have also been reported to contribute to immune dysfunction in conditions associated with increased risk of disease severity in COVID-19. There is a gap in our knowledge surrounding Th17-mediated protective immunity versus aberrant uncontrolled Th17-mediated pathology in the lung. This review aims to investigate and define the mechanisms of Th17 cells in COVID-19 pathogenesis by comparing the features of Th17 cells in a healthy immune response of the lung with the severe disease state in critical COVID-19.


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How to Cite

Connolly, S., & Basdeo, S. A. (2024). Defining the Role of Th17 Lineage Cells in People with COVID-19. Trinity Student Medical Journal , 22(1), 46–52. Retrieved from

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