Fig. 7.

CCR7 expression levels in rainbow trout intestinal CD8⁺DCs. Trout leukocytes obtained from rainbow trout intestine were isolated, stained with Abs to CD8α, MHC II and CCR7 and analyzed by multicolour flow cytometry. (A) Cells were first gated as lymphoid and myeloid cell on the basis of their FSC and SSC profile. Then CD8⁺ cells were gated on those populations and CCR7 fluorescence determined in CD8⁺ MHC II⁺ cells (open line histogram) and compared against the CCR7 levels of all other cells in that gate (filled line histogram). Numbers on histograms correspond to the percentage of CCR7⁺ cells after exclusion of negative cell of the conjugate-only controls (data not shown). Average percentage of CCR7⁺ cells (B) and MFI of CCR7 expression (C) in the intestinal lymphoid and myeloid populations were calculated and shown as mean + SD (n = 7). The percentage of CD8⁺ DCs expressing CCR7 expression (D) and MFI of CCR7 (E) were measured in gills and intestine and shown as mean + SD (n = 7). Statistical analyses were performed and asterisks denote significant differences between groups as indicated. *p ≤ 0.05 and **p ≤ 0.01.