Journal: Frontiers in Immunology

Article Title: Immunogenicity and protective efficacy of the HC009 mRNA vaccine against SARS-CoV-2

doi: 10.3389/fimmu.2024.1416375

Figure Lengend Snippet: Vaccine design and expression of the mRNA vaccine encoding COVID-19 spike. (A) Structure of HC009 RNA. UTR, untranslated region; CDS, coding domain sequence. (B) Lipid nanoparticle–mRNA formulations used as COVID-19 vaccines. (C) Spike protein expression by flow cytometry using biotinylated hACE2 protein. (D) Spike protein expression analyzed by Western blot using anti-spike as the primary antibody. The asterisk indicates a non-specific band. All data are representative of three independent experiments.

Article Snippet: Human embryonic kidney 293 cells (HEK293 cells) (ATCC CRL-3216) and HEK293T/hACE2-TMPRSS2 cells (SinoBiological, OEC003, China) were maintained in Dulbecco’s Modified Eagle’s Medium (DMEM, Gibco, 11965092, USA) supplemented with 10% fetal bovine serum (FBS, Gibco, 11965092, USA) and penicillin (100 U/mL)–streptomycin (100 mg/mL) (Gibco, 15140148, USA).

Techniques: Expressing, Sequencing, Vaccines, Flow Cytometry, Western Blot

Journal: Frontiers in Immunology

Article Title: Immunogenicity and protective efficacy of the HC009 mRNA vaccine against SARS-CoV-2

doi: 10.3389/fimmu.2024.1416375

Figure Lengend Snippet: Evaluation of the immune protection provided by HC009 during in vivo challenge. (A) Immunization and challenge procedures for the 0.5-, 2-, and 10-μg dose of HC009 in mice. Six- to 8-week-old female hACE2 transgenic mice were immunized with two doses of the vaccines via the intramuscular route at 3-week intervals ( n = 12). Subsequently, they were challenged with live SARS-CoV-2 at 50 days post-vaccination, and the lung and nasal turbinate tissues were collected at the indicated time points after immunization. (B) The body weights of the mice were monitored and recorded for six consecutive days after the challenge ( n = 6). The mice were euthanized after observation. (C) Average clinical scores for disease signs, including lethargy, ruffled fur, hunched back posture, and rapid breathing. A score of 1 was given to each of these clinical signs ( n = 12). (D) Viral RNA in the lungs and nasal turbinate tissues of challenged mice were measured with qRT-PCR at 1, 3, 5, and 6 dpi, respectively ( n = 6). (E) H&E staining was performed to assess pathological changes in the lungs of mice at 1, 3, 5, and 6 dpi ( n = 3). The data are shown as the mean ± SEM. Horizontal dashed line indicates the lower limit of quantification. All the data are representative of three independent experiments. A two-way ANOVA with Tukey’s multiple comparisons test was performed, * p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001.

Article Snippet: Human embryonic kidney 293 cells (HEK293 cells) (ATCC CRL-3216) and HEK293T/hACE2-TMPRSS2 cells (SinoBiological, OEC003, China) were maintained in Dulbecco’s Modified Eagle’s Medium (DMEM, Gibco, 11965092, USA) supplemented with 10% fetal bovine serum (FBS, Gibco, 11965092, USA) and penicillin (100 U/mL)–streptomycin (100 mg/mL) (Gibco, 15140148, USA).

Techniques: In Vivo, Transgenic Assay, Vaccines, Quantitative RT-PCR, Staining