Fig. 4: T cell responses induced by ICO-RBD nanovaccines in mice.

The mice were randomly divided into 3 groups and priming- and boost-vaccinated with the indicated vaccines at week 0 and 3, respectively. The spleens and lungs of mice were harvested at week 3 (before boost immunization) and 6. The harvested cells were stimulated with SpyCatcher-RBD proteins overnight. Proportions of IFN-γ⁺/IL-2⁺/TNF-α⁺ cells in CD3⁺CD8⁺ T cells (a) and CD3⁺CD4⁺ T cells (b) within the spleen, as detected using intracellular cytokine staining assays and flow cytometry (n = 6 mice). Proportions of IFN-γ⁺/IL-2⁺/TNF-α⁺ cells in CD3⁺CD8⁺ T cells (c) and CD3⁺CD4⁺ T cells (d) within the lung, as detected using intracellular cytokine staining assays and flow cytometry (n = 6 mice). Proportions of IL-4⁺ cells in CD3⁺CD4⁺ T cells within the spleen (e) and lung (f), as detected using intracellular cytokine staining assays and flow cytometry (n = 6 mice). g Percentages of CD69⁺CD103⁺ TRMs in CD8⁺ T cells in the lung, as detected using flow cytometry (n = 5 mice). The data were processed on GraphPad Prism 8 and are presented as the mean ± SD. Statistical significance (P value) was calculated by one-way ANOVA followed by Tukey’s test. *P < 0.05; **P < 0.01^; ***P < 0.001. ns, P  > 0.05, no significant difference. Source data are provided as a Source Data file.