Type I Interferons in SARS-CoV-2 Cutaneous Infection: Is There a Role in Antiviral Defense?

Area of Science:

• Dermatology
• Virology
• Immunology

Background:

• Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) primarily impacts the lungs, with limited understanding of its skin manifestations.
• The skin possesses intrinsic antiviral defense mechanisms, including Toll-like receptor (TLR) and interferon regulatory factor (IRF) pathway activation, and type I interferon (IFN) production.

Purpose of the Study:

• To investigate the presence and effects of SARS-CoV-2 in the skin of COVID-19 patients.
• To evaluate the cutaneous antiviral mechanisms and molecular responses to SARS-CoV-2 infection.

Main Methods:

• Skin samples from 35 deceased COVID-19 patients were analyzed.
• SARS-CoV-2 detection utilized transmission electron microscopy and RT-qPCR.
• Histopathology, RT-qPCR, and immunohistochemistry (IHC) assessed viral impact and molecular changes.

Main Results:

• SARS-CoV-2 was detected in skin, accompanied by microvascular thrombi, perivascular dermatitis, and eccrine gland necrosis.
• Increased TBK1 and reduced TNFα transcription were observed.
• Reduced ACE2, TLR7, and IL-6 expression, with elevated epidermal IFN-β, were noted. Dermal STING, IFN-β, and TNF-α decreased, while IL-6 increased in sweat glands.

Conclusions:

• The skin exhibits SARS-CoV-2 presence and associated histopathological changes.
• Type I interferon (IFN) is implicated in the cutaneous immune response to SARS-CoV-2, potentially modulating the skin's reaction to the virus.