Fig. 7

WCV-induced CD4⁺ TRM generated after parenteral immunization are sufficient to mediate neutrophil recruitment to the NM. Mice immunized with alum alone or WCV were left untreated, treated with FTY720, or treated with anti-CD4 antibody as indicated, challenged I.N. with pneumococcus, and nasal tissue was harvested 10 days later for analysis by immunofluorescent confocal microscopy. a Example of CD4⁺ (red) and MPO⁺ (green) immunofluorescent staining of cells in the nasal passages. Image = ×40 zoom. Quantitation of (b) CD4⁺ cells, and (c) MPO⁺ cells in the nasal passage. The results in (b and c) are a pool of two experiments, n = 3–5 mice for Alum, WCV, and WCV + FTY groups. Single experiment, n = 5 mice for WCV + anti-CD4 antibody group. Horizontal bars indicate the median value. * P < 0.05, **P < 0.01, ***P < 0.001