(1/n) The important role of natural killer (NK) cells in COVID-19.
A summary of key insights:
- NK cells are cytotoxic lymphocytes & part of the innate immune system
- They play an important role in virus infection control & immunomodulation

(2/n)
- The NK cell proliferation ability declines with age: older people have a decreased ability to produce NC cells rapidly: https://t.co/VZ9PSW5OBU

(3/n)
- As early as June 2020, it was hypothesised that NCCs could be key in explaining severe COVID-19 courses: https://t.co/yJPXeXcku0

(4/n)
- Indeed, it was later found that NK cells from COVID-19 patients do not function well:https://t.co/aEK9KpaA45

(5/n)
- The activity of NK cells is downregulated by the cytokine transforming growth factor-β (TGFβ)
- Blood serum of patients with severe COVID-19 inhibits NK cell function in a TGFβ-dependent manner: https://t.co/aEK9KpaA45