Journal: Frontiers in Immunology

Article Title: Mucosal multivalent NDV-based vaccine provides cross-reactive immune responses against SARS-CoV-2 variants in animal models

doi: 10.3389/fimmu.2025.1524477

Figure Lengend Snippet: Biodistribution of live NDV-HXP-S vaccine in Golden Syrian hamsters. (a) Experimental design and vaccination groups. Golden Syrian hamsters (n=12) were immunized with a total dose of 10 7 EID 50 of ancestral NDV-HXP-S via IN or IM route. Two more groups vaccinated with NDV LaSota (WT) via IN and PBS were used as controls. A total of 4 hamsters were analyzed per time point (b–e) At day 1 and day 7 after the vaccination, (b) lung homogenates, (c) nasal wash, (d) blood serum and (e) urine were collected and presence of infectious NDV was checked by injecting 100 µL of each biological fluid into each of the specific pathogen-free (SPF) embryonated chicken eggs. Viral titers were subsequently measured by EID 50 . (limit of detection equals to 100 EID 50 /mL; a titer of 10 EID 50 /mL was assigned to HA negative samples, and a titer of 50 EID 50 /mL was assigned to HA positive samples with no EID 50 /mL titer). (f-i) Left lobe was fixed in 4% paraformaldehyde in PBS (4% PFA, v/v) overnight and analyzed by immunohistochemistry (IHC) at day 1 and day 7 post vaccination. Presence of NDV viral protein or spike expression was measured with a rabbit polyclonal anti-NDV serum 1:2000 (shown in brown) or a human anti-SARS-CoV-2 spike 1A9 antibody 1:2000 (shown in pink). Examples of positively stained regions are indicated with arrows. Golden Syrian hamster lungs infected with SARS-CoV-2 (USA-WA1/2020), were used as spike staining positive control. The percentage of (g) NDV and (i) spike positive cells in each slide and (h) the percentage of NDV positive cells by airway in the two lung samples from the 1-day post administration of WT NDV group were measured with HALO software.

Article Snippet: The presence of NDV viral antigens was detected with a rabbit polyclonal serum (1:2000 dilution, brown) generated by Covance (labcorp, Princeton, NJ, USA) through immunization rabbit with adjuvanted inactivated NDV viruses and a human mAb 1A9 (Cat MA5-35946, Thermofisher) anti SARS-CoV-2 spike antibody (1:2000 dilution, pink).

Techniques: Immunohistochemistry, Expressing, Staining, Infection, Positive Control, Software

Journal: Nature Communications

Article Title: Factor Xa cleaves SARS-CoV-2 spike protein to block viral entry and infection

doi: 10.1038/s41467-023-37336-9

Figure Lengend Snippet: a The binding affinity of FXa with full-length wild-type S protein, subunit S1, subunit S2, or RBD was quantified by ELISA ( n = 9 biologically independent samples). Bounds of box is from 25% percentile to 75% percentile, horizontal bar indicates median, and whiskers indicate data ranges. b The binding affinity of FXa to VSV-SARS-CoV-2 viral particles was quantified by ELISA ( n = 3 biologically independent samples). c The interaction between FXa protein and full-length S protein was examined with a pull-down assay. d The binding affinity at indicated concentrations of FXa was measured by ELISA ( n = 3 biologically independent samples). e The cleavage of S protein by furin, TMPRSS2, and FXa after 3-hour incubation was analyzed by immunoblotting using an anti-S protein antibody (40591-T62, Sino Biological). f S protein was cleaved by FXa, followed by immunoblotting with an anti-RBD antibody (MAB10540-100, R&D) (left) and an anti-S2 antibody (MA5-35946, Invitrogen) (right). g The cleavage of VSV-SARS-CoV-2 by FXa or furin was analyzed by immunoblotting using an anti-S protein antibody (40591-T62, Sino Biological). The larger size of S protein from VSV-SARS-CoV-2 (~200 kD) compared to recombinant S protein (~150 kD) may be due to the glycosylation of the former. All data are representative of at least three independent experiments. a , b , d , data are presented as mean values ± SD. Statistical analyses were performed by two-sided Student’s t test ( b ) or one-way ANOVA models ( a ). Source data are provided as a Source Data file.

Article Snippet: For evaluating the cleavage fragments, anti-RBD antibody (MAB10540-100, R&D) and anti-S2 subunit antibody (MA5-35946, Invitrogen) were used at the 1:1000 dilution.

Techniques: Binding Assay, Enzyme-linked Immunosorbent Assay, Pull Down Assay, Incubation, Western Blot, Recombinant