Fig. 5

Exploration of potential receptors in T cells. a The expression of ACE2, TMPRSS2, and ITGB2 (LFA-1) in blood T cells from healthy donors and COVID-19 patients. The analysis is dependent on public single-cell NGS data.¹⁴ The expression of the three genes is indicated in SARS-CoV-2 viral RNA-positive T cells for patient penal. b BEAS-2B and activated Jurkat cells were incubated with different concentrations of AXL proteins (25, 50, or 100 μg/ml) at 37 °C for 30 min before infected by SARS-CoV-2 (MOI of 0.01). Intracellular viral RNA (RBD) at 24 h post infection was quantified using qPCR. c Knockdown or overexpression of AXL were performed on Jurkat cells and the expression level of AXL was detected using qPCR. Cell lines were infected by SARS-CoV-2 at an MOI of 0.01 for 24 h and viral RNA was quantified. d LFA-1 was stably overexpressed on ACE2 knockdown Caco2 (Caco2-ACE2-shRNA) or Jurkat cells, and the RNA level was quantified using qPCR. e Caco2, activated Jurkat and their respective LFA-1-overexpression cells were infected by SARS-CoV-2 at an MOI of 0.01 and harvested at 24 h post infection. Intracellular viral RNA was detected using qPCR. f, g Caco2, Caco2-ACE2-shRNA, and its LFA-1 overexpression cell line were infected by SARS-CoV-2 at an MOI = 5 for 8 h. The high content microscope was used to observe (f) and quantify (g) the viral NP-positive cells. h LFA-1 knockdown Jurkat cells were infected with SARS-CoV-2 (MOI = 0.01) for 24 h, and the expression of LFA-1 and intracellular viral RNA was analyzed using qPCR. i Activated Jurkat cells were pretreated with Lifitegrast, an inhibitor of LFA-1 at different concentrations (50, 100, or 200 nM) at 37 °C for 30 min before infection (MOI = 0.01). Intracellular viral RNA was quantified at 24 h post infection. The statistics was performed using Student’s t test (*P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001; NS no significance)