parental hek 293 cells  (ATCC)

Journal: Nature Communications

Article Title: Circulating ACE2-expressing extracellular vesicles block broad strains of SARS-CoV-2

doi: 10.1038/s41467-021-27893-2

Figure Lengend Snippet: Summary of sero-negative, acute, and convalescent-phase of COVID-19 patients from which the plasma ACE2 + EVs and RBD-IgG levels were measured.

Article Snippet: The parent ACE2 − human embryonic kidney HEK-293 cells (HEK) (ATCC, CRL-1573) or human cervical cancer HeLa cells (HeLa) (ATCC, CRM-CCL-2) are transduced with a lentiviral pDual-ACE2 expression vector for stable ACE2 expression and production of ACE2 + EVs.

Techniques: Clinical Proteomics, Sampling

Journal: Nature Communications

Article Title: Circulating ACE2-expressing extracellular vesicles block broad strains of SARS-CoV-2

doi: 10.1038/s41467-021-27893-2

Figure Lengend Snippet: a ACE2+ EVs detected in human plasma samples of sero-negative controls (light blue), acute phase (dark green), and convalescent COVID-19 patients (green). One-tail t test (* p = 0.038, ** p = 0.0061 and ** p = 0.0016). Data are presented as mean values ± SEM. b Representative microflow vesiclometry (MFV) plots with gated ACE2+ EVs from sero-negative, acute phase and convalescent COVID-19 patients. c MFV detection of circulating ACE2 + EVs with CD63 + EVs in human plasma of convalescent COVID-19 patient samples (CSB-029 and CSB-023) (green line). Blue line is isotype IgG-negative control. d Flow profiles of ACE2 expression in HEK and HeLa parental control cells (Con, light blue line, ACE2 − ) and with ACE2 overexpression (ACE2, green line). e NanoSight NTA analysis of the sizes of HEK-derived ACE2 − (ev1Con) and ACE2 + (ev1ACE2) and HeLa-derived ACE2 − (ev2Con) and ACE2 + (ev2ACE2). f Immunoblots of HEK and HeLa (ACE2 − and ACE2 + ) EVs and cell lysates for ACE2, TSG101, CD63, CD81, GRP94 and loading control of the membrane proteins upon Ponceau staining. RIPA buffer and Bradford protein assay were used for cells/EVs lysis and protein measurement, respectively ( N = 1 experiment). g Cryo-EM images of HEK-derived EVs, ACE2 − (evCon, left) and ACE2 + (evACE2, right), stained with ACE2 (top) and CD81 (bottom). Scale bars = 100 nm. h Quantified counts of Apogee MFV-based total extracellular vesicles (EVs) and ACE2 + EVs ( N = 2 experiments with n = 6 technical replicates for total EV particles and n = 3 technical replicates for ACE2 + counts). Control EVs are in light blue and ACE2 + EVs in green. Data are presented as mean values +/− SD. i Overlay flow profiles of ACE2 positivity within CD63 + (left column) and CD81+ (right column) EVs isolated from HEK-ACE2 (top row) and HeLa-ACE2 (bottom row) cells, respectively ( n = 3 technical replicates). Light blue line for Control EVs and green line for ACE2 + EVs.

Article Snippet: The parent ACE2 − human embryonic kidney HEK-293 cells (HEK) (ATCC, CRL-1573) or human cervical cancer HeLa cells (HeLa) (ATCC, CRM-CCL-2) are transduced with a lentiviral pDual-ACE2 expression vector for stable ACE2 expression and production of ACE2 + EVs.

Techniques: Clinical Proteomics, Negative Control, Expressing, Control, Over Expression, Derivative Assay, Western Blot, Membrane, Staining, Bradford Protein Assay, Lysis, Cryo-EM Sample Prep, Isolation

Journal: Nature Communications

Article Title: Circulating ACE2-expressing extracellular vesicles block broad strains of SARS-CoV-2

doi: 10.1038/s41467-021-27893-2

Figure Lengend Snippet: a Schematic depiction of the cell-based neutralization assay. b Representative flow profiles showing the percentage (fluorescence mean intensity) of RBD-AF647 binding (at 16 and 3.3 nmol/L) to ACE2 + HEK-293 cells, inhibited by rhACE2 and ACE2 + EVs (evACE2) isolated from HEK-293 and HeLa cells (HEK-EV1 and HeLa-EV2, respectively) whereas ACE2 − EVs (evCon) had no neutralization effects (no RBD in black, PBS in dark blue, rhACE2 in orange, evCon in light blue, and evACE2 in green). c IC 50 of rhACE2 (orange line) and ACE2 in the EVs from ACE2 + HEK (ev1ACE2) and HeLa (ev2ACE2) cells (green lines) on 16 nM RBD-host cell binding (%). GraphPad Prism 9.0.2 was used to calculate the IC 50 . N = 2 experiments with two technical replicates for each. Data are presented as mean values ± SD. d IC 50 of evACE2, ev1 from HEK and ev2 from HeLa cells (green lines), and rhACE2 (orange line) neutralizing infections by wild-type (WT) S + pseudotyped SARS-CoV-2. GraphPad Prism 9.0.2 was used to calculate the IC 50 . N = 2 experiments with two technical replicates for each. Data are presented as mean values ± SD. e IC 50 (nM) of ACE2 in ev1ACE2 (HEK) (green line) and rhACE2 (orange line) upon wild-type SARS-CoV-2 infection. GraphPad Prism 9.0.2 was used to calculate the IC 50 with three biological replicates. Data are presented as mean values ± SD. f Distinct effects of ACE2 + EVs (green lines) and ACE2 − control EVs (light blue line) on inhibiting Vero-6 cell death caused by SARS-CoV-2. N = 2 experiments with three biological replicates each. Data are presented as mean values ± SD. g The IC 50 of ev1ACE2 (HEK) neutralizing infections by pseudotyped SARS-CoV-2 expressing WT (black), B.1.1.7 (α) variant (red), B1.351 (β) variant (dark blue) and B.1.617.2 (δ) (light green) S protein. GraphPad Prism 9.0.2 was used to calculate the IC 50 . N = 2 experiments with two technical replicates each. Data are presented as mean values ± SD. h Effects of ev1ACE2 (HEK) on protecting Vero-6 cell viability against infections of SARS-CoV-2 WT (black), B.1.1.7 (α) variant (red) and B1.351 (β) variant (dark blue) ( n = 3 biological replicates). Data are presented as mean values ± SD.

Article Snippet: The parent ACE2 − human embryonic kidney HEK-293 cells (HEK) (ATCC, CRL-1573) or human cervical cancer HeLa cells (HeLa) (ATCC, CRM-CCL-2) are transduced with a lentiviral pDual-ACE2 expression vector for stable ACE2 expression and production of ACE2 + EVs.

Techniques: Neutralization, Fluorescence, Binding Assay, Isolation, Infection, Control, Expressing, Variant Assay

Journal: Nature Communications

Article Title: Circulating ACE2-expressing extracellular vesicles block broad strains of SARS-CoV-2

doi: 10.1038/s41467-021-27893-2

Figure Lengend Snippet: a Schematic depiction of plasma EV ultracentrifugation and RBD-bead based depletion. b Cryo-EM images of human EV pellets isolated from acute phase COVID-19 plasma (bar = 100 nm). c Immunoblots of plasma EV pellets (sero-negative and COVID-19 acute phase patients CBB-005 and -013) for ACE2 and loading control of protein staining with Ponceau). Laemmli buffer was used for lysis ( N = 1 experiment). d ACE2 + EV pellets from acute phase patients 007, 008, 009, 012, and 013 (CBB) ( n = 2 biological replicates each) blocked SARS-CoV-2 infection-induced death of Vero-6 cells whereas the sero-negative control ( n = 2 biological replicates) and CBB-005 (no detectable ACE2) ( n = 2 biological replicates) did not show neutralization effects. One-tail t test, **** p = 2.24E−08 shown as compared to sero-negative. e , f Levels of ACE2 + EV counts ( n = 3 biological replicates) in plasma EVs (green) and bead-depleted EVs (light blue). One-tail paired t test, * p = 0.011 and ** p = 0.0063 (data are presented as mean values ± SD) ( e ) and altered neutralization effects on RBD–host cell binding ( f ) of the COVID-19 plasma EV pellets prior to and after RBD-bead depletion (convalescent phase CSB-012 and -024; acute phase CBB-008, 009, and 013). One-tail paired t test **** p = 5.11E−05.

Article Snippet: The parent ACE2 − human embryonic kidney HEK-293 cells (HEK) (ATCC, CRL-1573) or human cervical cancer HeLa cells (HeLa) (ATCC, CRM-CCL-2) are transduced with a lentiviral pDual-ACE2 expression vector for stable ACE2 expression and production of ACE2 + EVs.

Techniques: Clinical Proteomics, Cryo-EM Sample Prep, Isolation, Western Blot, Control, Staining, Lysis, Infection, Negative Control, Neutralization, Binding Assay

Journal: Nature Communications

Article Title: Circulating ACE2-expressing extracellular vesicles block broad strains of SARS-CoV-2

doi: 10.1038/s41467-021-27893-2

Figure Lengend Snippet: a Probability of severe disease-free survival in B6.Cg-Tg(K18-ACE2)2Prlmn/J (K18-hACE2) mice receiving SARS-CoV-2 infection (10,000 pfu) and intranasal EVs (130 µg as measured on Nanodrop) per mouse (evCon in light blue and evACE2 in green). Log-rank (Mantel–Cox) and Gehan–Breslow–Wilcoxon tests **** p = 2.27E−07. b Viral loads in mouse lungs on day 5/6 after receiving SARS-CoV-2 infection and administration of evCon ( N = 5 mice) (light blue) or evACE2 ( N = 10 mice) (green). T -test–nonparametric-one tailed, * p = 0.013. Data are presented as mean values ± SD. c . Representative H&E images of mouse lung sections at day 5 or 6 post virus inoculation and EV treatment (evCon and evACE2) intranasally. d , e Acute and chronic inflammation scores ( d ), and alveolar hemorrhage and necrosis scores ( e ) in mouse lungs on day 5/6 after receiving evCon ( N = 5 mice) (light blue) or evACE2 ( N = 7 mice) (green). T -test–nonparametric-one tailed, ** p = 0.005, ** p = 0.003 and *** p = 0.0004. Data are presented as mean values ± SD.

Article Snippet: The parent ACE2 − human embryonic kidney HEK-293 cells (HEK) (ATCC, CRL-1573) or human cervical cancer HeLa cells (HeLa) (ATCC, CRM-CCL-2) are transduced with a lentiviral pDual-ACE2 expression vector for stable ACE2 expression and production of ACE2 + EVs.

Techniques: Infection, One-tailed Test, Virus