Figure 6.

Depletion of TCRγδ cells reduces IL-17 expression, increases Th17⁺ total cell number and prevents intestinal and joint inflammation induced by Salmonella enterocolitis. Wild type BALB/c mice pretreated with 20 mg of streptomycin received 3−4 × 10³ CFU of Salmonella. Samples were taken 5 days post-infection. Flow cytometry. The number of Th17 cells was identified by CD3⁺CD4⁺ double positive cells and gated by intracellular staining of IFN-γ⁻ IL-17⁺. Percentage of Th17 cells (solid bars) and IL-17 expression in mesenteric lymph nodes (stripped bars) (A). Interleukin expression was determined by qPCR, levels for mRNA were analyzed by qPCR in mesenteric lymph nodes and are presented in relation to 18S rRNA. EC group: mice suffering from enterocolitis, Anti-γδ EC: Salmonella infected mice treated with anti-TCRγδ mAb. Anti-γδ group: uninfected animals treated with anti-TCRγδ mAb. Control group: uninfected untreated mice. ^¥Significant differences in the percentage of Th17 cells with respect to the other three groups (p < 0.05). ^*Significant differences in IL-17 expression with respect to the other three groups (p < 0.01); NS, no significant differences. Results are expressed as mean ± SD (n = 4). Representative data from 3 independent experiments. Representative HE sections of intestine (B–D) and knee joint (E–G). EC group (B,E). Anti-γδ EC group (D,G); Control group (C,F). Arrows indicate synovial membrane. Scale bar 100 m.