Fig. 2

Intranasal immunization with PR8.p25 induces the persistence of CD69⁺ CD11a⁺ p25 CD4⁺ T cells in the lung parenchyma. Fifty-thousand CD45.1⁺ P25 or GFP-P25 Tg splenic cells were adoptively transferred into naive recipient C57Bl/6 mice 1 day prior to immunization intranasally with 20 pfu PR8.p25. Kinetics of the total CD4 + T cells (a) and of the transferred CD45.1⁺ P25 CD4⁺ T cells (b) in the lung after immunization with PR8.p25. c Expression of CD69 and CD103 by the P25 CD4 T cells. d Intravascular staining of the CD3⁺CD4⁺ population showing the CD45-unlabeled GFP-P25 T cells located in the lung parenchyma (quadrant I) and the vascular CD45-labeled GFP-P25 T cells (quadrant II), e CD69 expression profile in parenchymal (blue) vs. vascular (red) GFP-P25 T cells, f expression of CD69 and CD11a and g CD44 and CD62L in GFP-P25 parenchymal cells, and h numbers of parenchymal GFP-P25 cells expressing CD69 and CD11a at 8 weeks after immunization with PR8.p25. The data are representative of 1 of 2 independent experiments and are presented as mean ± SEM (n = 3–5)