Fig. 3

SARS-CoV-2 infection of T cell is spike-ACE2/TMPRSS2-independent. a The ACE2 expression level of Scramble or ACE2-knockdown Caco2 or Jurkat cells was analyzed by qPCR or WB. b ACE2 stably knockdown Caco2 or activated Jurkat cells were infected with SARS-CoV-2 (MOI = 0.01). Viral RNA or viral NP in cells was analyzed by qPCR or WB at 24 h post infection. c The ACE2 expression level of control or ACE-knockout Caco2 or Jurkat cells were quantified by qPCR or detected by WB. d ACE2 stably knock-out Caco2 or activated Jurkat cells were infected with SARS-CoV-2 (MOI = 0.01). Viral RNA or viral NP was detected using qPCR or WB. e For ACE2 blocking, Caco2 or activated Jurkat cells were pre-incubated with anti-ACE2 Ab (3.33 ng/μl final) before infected with SARS-CoV-2. For virus blocking, ACE2-Fc protein (10 μg/μl final) or RD#4-anti-Spike Ab (160 ng/μl final) were incubated with SARS-CoV-2 at a volume of 1:1 at 37 °C for 30 min. Cells were infected at 0.01 MOI for 24 h before they were quantified for SARS-CoV-2 viral RNA or NP protein by qPCR or WB. f The TMPRSS2 expression level of Caco2, Jurkat and activated Jurkat cells was analyzed using qPCR. g Caco2 or activated Jurkat cells were pre-incubated with Camostat (2 μM or 20 μM) for 1 h and then infected with SARS-CoV-2 (MOI = 0.01). Viral RNA or NP proteins were quantified. The results were derived from three independent experiments. Statistical analyses were carried out using Student’s t test (*P < 0.05; **P < 0.01; ****P < 0.0001; NS no significance)