Evasion of NKG2D-mediated cytotoxic immunity by sarbecoviruses

Jordan A. Hartmann, Marcella R. Cardoso, Maria Cecilia Ramiro Talarico, Devin J. Kenney, Madison R. Leone, Dagny C. Reese, Jacquelyn Turcinovic, Aoife K. O'Connell, Hans P. Gertje, Caitlin Marino, Pedro E. Ojeda, Erich V. De Paula, Fernanda A. Orsi, Licio Augusto Velloso, Thomas R. Cafiero, John H. Connor, Alexander Ploss, Angelique Hoelzemer, Mary Carrington, Amy K. BarczakNicholas A. Crossland, Florian Douam, Julie Boucau, Wilfredo F. Garcia-Beltran

Research output: Contribution to journalArticlepeer-review


SARS-CoV-2 and other sarbecoviruses continue to threaten humanity, highlighting the need to characterize common mechanisms of viral immune evasion for pandemic preparedness. Cytotoxic lymphocytes are vital for antiviral immunity and express NKG2D, an activating receptor conserved among mammals that recognizes infection-induced stress ligands (e.g., MIC-A/B). We found that SARS-CoV-2 evades NKG2D recognition by surface downregulation of MIC-A/B via shedding, observed in human lung tissue and COVID-19 patient serum. Systematic testing of SARS-CoV-2 proteins revealed that ORF6, an accessory protein uniquely conserved among sarbecoviruses, was responsible for MIC-A/B downregulation via shedding. Further investigation demonstrated that natural killer (NK) cells efficiently killed SARS-CoV-2-infected cells and limited viral spread. However, inhibition of MIC-A/B shedding with a monoclonal antibody, 7C6, further enhanced NK-cell activity toward SARS-CoV-2-infected cells. Our findings unveil a strategy employed by SARS-CoV-2 to evade cytotoxic immunity, identify the culprit immunevasin shared among sarbecoviruses, and suggest a potential novel antiviral immunotherapy.

Original languageEnglish (US)
Pages (from-to)2393-2410.e14
Issue number10
StatePublished - May 9 2024
Externally publishedYes


  • COVID-19
  • cytotoxic
  • lymphocytes
  • MIC-A/B
  • NK cells
  • NKG2D
  • sarbecoviruses
  • SARS-CoV-2

ASJC Scopus subject areas

  • General Biochemistry, Genetics and Molecular Biology


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