Figure 3
Target cell lysis, binding of RSV M2-pentamer and reduction in viral titers by CD8+T cells following RSV infection. Lungs were harvested on day 8 after RSV infection and CD8+11c+ or CD8+11c- cells were isolated. A) CFSE labeled effector and unlabeled P815 target cells were incubated at the indicated ratios for 4 hours. Subsequently the percentage of unlabeled cells, staining positive for 7-AAD, was determined by FACS and B) specific lysis was calculated (mean ± SD, n = 4, significant difference of * CD11c+ (open squares) versus CD11c- cells (open circles) or # anti-CD11c-mAb pretreated CD11c+ (filled triangles) versus CD11c- cells, p < 0.05) C) Freshly isolated lung cells were stained with anti-CD8, anti-CD11c and RSV M2-pentamer. Dot plots show expression of CD11c without or with RSV M2-pentamer staining on cells gated for CD8 expression. D) Isolated CD8+11c+ or CD8+11c- cells (2.5 × 105) were adoptively transferred to the lungs 1 hour after RSV infection of recipients. Controls only received PBS intra-tracheally after infection. Lung RSV titers were determined by plaque assay on dpi 4. Depicted are mean ± SD from 2 independent experiments (n = 6, * significant difference, p < 0.05, CD11c+ (black bar) versus PBS group (open bar) and CD11c- cells (hatched bar).