Journal: medRxiv

Article Title: SARS-CoV-2 mRNA vaccination exposes progressive adaptive immune dysfunction in patients with chronic lymphocytic leukemia

doi: 10.1101/2022.12.19.22283645

Figure Lengend Snippet: (A and B) Comparison of SARS-CoV-2 vaccine-elicited spike (A) and RBD (B) ELISA IgG antibody titers in HC (n=30) and CLL (n=95) patients expressed as half-maximal effective concentrations (EC 50 ). (C and D) SARS-CoV-2 vaccine-elicited spike (C) and RBD (D) ELISA IgG antibody titers stratified by CLL disease status: treatment-naïve (Naïve) (n=45), on-therapy (On Tx) (n=34), off-therapy in clinical remission (CR) (n=9), and off therapy and relapsed or refractory (R/R) (n=7). (E-G) Comparison of SARS-CoV-2 vaccine-elicited neutralizing antibody titers for HC (n=30) and CLL patients against (E) D614G (CLL; n=95) and (F) delta (CLL; n=93) spike variants expressed as the reciprocal half-maximal inhibitory dilution (ID 50 ) as determined in an HIV-based pseudovirus neutralization assay or by (G) ACE2/RBD (Wuhan) binding inhibition (CLL; n=95) at a 1:25 dilution. (H-J) SARS-CoV-2 vaccine elicited NAb titers for D614G (H) and delta (I) S variants and ACE2/RBD binding frequencies (J) stratified by CLL disease status. Bars indicate the median with 95% CI. Dotted black lines indicate assay sensitivity cutoffs (EC 50 values of <100 by ELISA, ID 50 values of <20 in the neutralization assay, and >90% ACE2 binding in the RBD-inhibition assay). P values were determined by the Mann-Whitney test (A-B, E-G) or Dunn’s test of multiple comparisons following a Kruskal-Wallis test (C-D, H-J).

Article Snippet: Plates were incubated at room temperature for 1 h, washed 4 times with PBST, and 50 µl of biotinylated goat anti-human ACE2 (R&D) diluted at 0.1 µg/ml in PBST was added to the wells.

Techniques: Enzyme-linked Immunosorbent Assay, Neutralization, Binding Assay, Inhibition, MANN-WHITNEY

Journal: International Journal of Molecular Sciences

Article Title: Molecular Interactions of Tannic Acid with Proteins Associated with SARS-CoV-2 Infectivity

doi: 10.3390/ijms23052643

Figure Lengend Snippet: Inhibitory effects of different polyphenols on the interaction between SARS-CoV-2 spike protein receptor binding domain (RBD (N501Y)) and human angiotensin-converting enzyme 2 (ACE2). ( A ) 10 µM of pelargonidin-3-O-glucoside (Pel-3-O-G), malvidin-3-O-glucoside (Mal-3-O-G), cyanidin-3-O-glucoside (Cya-3-O-G), peonidin, tannic acid (TA), 1,3,6-tri-O-galloyl-β-D-glucose (TGG), and corilagin were tested to evaluate their ability to inhibit the binding of immobilized spike protein (0.5 µg/mL) to human, biotin-labeled ACE2 (0.25 µg/mL) by using an enzyme-linked immunosorbent assay (ELISA). Dose effect inhibition of 0.1, 1, and 5 µM ( B ) TA, ( C ) TGG, and ( D ) corilagin. The absorbance of ACE2 (0.25 µg/mL) at 450 nm was set to 100%. Results are expressed as mean ± SD (n = 3). Statistical analysis was performed using one-way ANOVA followed by the Tukey post hoc test with * p < 0.05, ** p < 0.01, *** p < 0.001 compared to ACE2 (0.25 µg/mL).

Article Snippet: Biotinylated recombinant human ACE2 with purity >95% and camostat mesylate compound were both purchased from R&D Systems (Minneapolis, MN, USA).

Techniques: Binding Assay, Labeling, Enzyme-linked Immunosorbent Assay, Inhibition

Journal: bioRxiv

Article Title: A Novel Regioselective Approach to Cyclize Phage-Displayed Peptides in Combination with Epitope-Directed Selection to Identify a Potent Neutralizing Macrocyclic Peptide for SARS-CoV-2

doi: 10.1101/2022.07.06.498864

Figure Lengend Snippet: Selection of macrocyclic peptide ligands for the SARS-CoV-2 Spike RBD. A) Loops of the Spike RBD (beige) involved in recognition of ACE2 (Cyan) were identified for screening. P28 corresponds to the green residues and P29 corresponds to the magenta residues. B) The most abundant peptides from the selections against P28 and P29 are shown. Percent abundance corresponds to the percent of each sequence after the third round of selection against the corresponding peptides. Each peptide was analyzed for binding to the Spike RBD using BLI and the reported K D values are given as mean ± SD of three independent experiments.

Article Snippet: These were then added to AlphaScreen plates (Perkin Elmer, 384-well) that had been preincubated for 30 minutes with 12.5 μL of Biotinylated-ACE2 (Sino Biological, Cat. No. 10108-H27B-B).

Techniques: Selection, Sequencing, Binding Assay

Journal: bioRxiv

Article Title: A Novel Regioselective Approach to Cyclize Phage-Displayed Peptides in Combination with Epitope-Directed Selection to Identify a Potent Neutralizing Macrocyclic Peptide for SARS-CoV-2

doi: 10.1101/2022.07.06.498864

Figure Lengend Snippet: Characterization of macrocyclic peptides for inhibition of interactions between the Spike RBD and ACE2. A) Assays used to characterize inhibition consisted of an AlphaScreen assay to measure protein-protein interactions along with a cytopathogenic effect (CPE) assay that quantified infectivity of SARS-CoV-2 in Vero E6 cells. B) Inhibition of Spike RBD:ACE2 interactions by P29S1 using the AlphaScreen assay. Data points are presented as mean ± SEM of four biologically independent replicates (N=3). C) Live virus inhibition using P29S1 (red) and P28S1 (blue). Data points are presented as mean ± SD of three biologically independent experiments (N = 3). D) Summary of inhibition data for each of the tested peptides. NI = No inhibition. ND = Not determined. All data is reported as mean ± SD for three independent experiments (N = 3).

Article Snippet: These were then added to AlphaScreen plates (Perkin Elmer, 384-well) that had been preincubated for 30 minutes with 12.5 μL of Biotinylated-ACE2 (Sino Biological, Cat. No. 10108-H27B-B).

Techniques: Inhibition, Amplified Luminescent Proximity Homogenous Assay, Infection