Interleukin-17A (IL-17A): A silent amplifier of COVID-19

Abstract

One of the hallmarks of COVID-19 is the cytokine storm that provokes primarily pneumonia followed by systemic inflammation. Emerging evidence has identified a potential link between elevated interleukin-17A (IL-17A) levels and disease severity and progression. Considering that per se , IL-17A can activate several inflammatory pathways, it is plausible to hypothesize an involvement of this cytokine in COVID-19 clinical outcomes. Thus, IL-17A could represent a marker of disease progression and/or a target to develop therapeutic strategies. This hypothesis paper aims to propose this “unique” cytokine as a silent amplifier of the COVID-19 immune response and (potentially) related therapy.

Up-regulated serum levels of interleukin (IL)-17A and IL-22 in Egyptian pediatric patients with COVID-19 and MIS-C: Relation to the disease outcome

“…In contrast to our study, elevated levels of serum IL-17A were reported to be associated with the disease severity and progression [32] . Although the inflammatory markers are considered non-specific in patients with COVID-19 infection, serum levels of IL-6 and CRP were reported to predict the outcome in patients with COVID-19 infection [33] .…”

Integration and Reanalysis of Four RNA-Seq Datasets Including BALF, Nasopharyngeal Swabs, Lung Biopsy, and Mouse Models Reveals Common Immune Features of COVID-19

“…Released from activated T H 17 cells, IL-17 has been identified as a potent effector cytokine towards pulmonary hyperinflammation during COVID-infection. IL-17 exerts its effect through activation of multiple signalling pathways and transcription factors, particularly NF k B, promoting additional pro-inflammatory cytokines and chemokines of alveolar and epithelial origin, hence leading to potentially lethal cytokine storm ( 27 28 ). Akin to IL-17, significant expression of TNFα by infected tissues, innate immune cells, and T H 17 detected in serum showed a strong positive correlation to COVID-19 severity and mortality ( 29 30 ).…”

Enhanced SARS-CoV-2-Specific CD4+ T Cell Activation and Multifunctionality in Late Convalescent COVID-19 Individuals

“…Published reports explain there was an altered TNF-α response seen during COVID-19 infection [ 40 ] IL-17 play a key role in the pathogenesis of multiple inflammatory and autoimmune disorders [ 42 ]. Studies have also shown that increased levels of IL-17A are a silent amplifier of the COVID-19 immune responses [ 43 ]. In our study, we evaluated the dynamics and durability of SARS-CoV-2 antigen specific T cell responses in early and late COVID-19 convalescent individuals.…”