Fig. 2: Immunization with Spike-LP-GMP by i.n. route elicits CD4⁺ T_RM and Tfh cells in the respiratory mucosa.

Mice were immunized as described in Fig. 1, lung and nasal tissue samples were collected on day 35. a Number of CD4⁺ T_RM cells (CD44⁺CD62L^-CD45^-CD69⁺) in the lung and nasal tissue. b Representative flow cytometry plot of lung CD4⁺ T_RM cells. c-f Number of Spike-specific CD4⁺ T_RM cells secreting IFN-γ c, TNF d, IL-17 e, or GrB f in the lung and nasal tissue following 18 h stimulation with Spike trimer (2.5 µg/ml). g Representative flow cytometry plot of IL-17 and TNF secreting lung CD4⁺ T_RM cells. h Number of CD4⁺ Tfh cells in the lung and nasal tissue. Data were analyzed by one-way ANOVAs followed by post hoc Tukey’s test for multiple comparisons (*P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001), error bars, SEM. Results are representative of three independent experiments.