Journal: PLOS Pathogens

Article Title: A circular RNA vaccine induces durable and cross-protective immunity against Neisseria meningitidis serogroup B in mice

doi: 10.1371/journal.ppat.1013741

Figure Lengend Snippet: (A) Immunization scheme. BALB/c mice (n = 5 per group) received three intramuscular or subcutaneous injections of circVB16T13 or recombinant VB16T13 protein emulsified with Freund’s adjuvant at 2-week intervals. Sera, spleens, and inguinal lymph nodes (ILNs) were harvested at indicated timepoints for immune analyses. This figure was created using Figdraw ( www.figdraw.com ) with permission. (B) Antigen-specific serum IgG endpoint titers measured 2 weeks after the prime, first boost, and second boost immunizations. Data are log10-transformed. Bars represent geometric mean titer (GMT) with 95% CI. The dashed line indicates the limit of detection. (C) Human serum bactericidal activity (hSBA) titers in pooled serum against N. meningitidis strain MC58 at 2 weeks after each immunization. The pooled serum samples were assayed in technical replicates (n = 3). Bars indicate the GMT and error bars indicate geometric SD of technical replicates. The dashed line denotes the protective threshold (hSBA = 4). (D, E) Serum IgG subclass ratios: IgG2a/IgG1( D ), IgG2b/IgG1( E ). Horizontal lines denote mean values. (F-H) Flow cytometry analysis of ILN immune subsets 2 weeks after the second boost. (F) Tfh cells (CD4 + CD44 + PD-1 + CXCR5 + ). (G) Germinal center B cells (CD45 + CD45R + GL7 + Fas + ). (H) Memory B cells (CD45 + CD45R + IgG1 + CD38 + ). (I, J) Cytokine production by splenic T cells collected 2 weeks after the second boost. Frequencies of CD4 + T cells ( I ) and CD8 + T cells ( J ) secreting IL-2, TNF-α, and IFN-γ after 24-hour stimulation with VB16T13 protein, measured by intracellular cytokine staining (ICS). Comparisons among more than two groups were conducted by one-way ANOVA (F-H) and Two-way ANOVA comparison tests (B, I, J) .

Article Snippet: N. meningitidis MC58 strain (ATCC BAA-335) was purchased from ATCC.

Techniques: Recombinant, Adjuvant, Transformation Assay, Activity Assay, Flow Cytometry, Staining, Comparison

Journal: PLOS Pathogens

Article Title: A circular RNA vaccine induces durable and cross-protective immunity against Neisseria meningitidis serogroup B in mice

doi: 10.1371/journal.ppat.1013741

Figure Lengend Snippet: (A) Experimental design for N. meningitidis serogroup B strain MC58 challenge. BALB/c mice (n = 5 per group) were infected intraperitoneally with 2 × 10 6 CFU at 14 days after the final immunization. This figure was created using Figdraw ( www.figdraw.com ) with permission. (B) Kinetics of bacteremia in pooled whole blood following challenge. Bacterial loads were quantified at 1, 3, 6, 9, and 12 hours post infection. The dashed line indicates the limit of detection (LOD = 500 CFU/mL). Values under the LOD were assigned a value of 250 CFU/mL (LOD/2) for statistical analysis. (C) Survival curves of mice monitored for 13 days post infection. (D, E) Histopathological analysis of tissues at 13 days post infection. Naïve and iron-supplemented groups were uninfected and served as baseline controls. (D) Representative H&E-stained lung sections. Black arrows indicate hemorrhage, red arrows indicate inflammatory cells, and blue arrows indicate septal thickening. (E) Representative H&E-stained brain sections. Red arrows indicate inflammatory cells. Scale bars, 50 μm. Comparisons among more than two groups were conducted by one-way ANOVA comparison tests (D , E) . Comparisons of the survival data were conducted by Log-rank (Mantel-Cox) tests (C) .

Article Snippet: N. meningitidis MC58 strain (ATCC BAA-335) was purchased from ATCC.

Techniques: Infection, Staining, Comparison