Figure 2. Absence of donor-derived IL-17 has no protective effect on the development of autoimmunity.

Lethally irradiated Balb/c mice were transplanted with BM (10 × 10⁶) and spleen cells (0.4 × 10⁶) from wild type B6 or IL-17^−/− animals to induce GVHD. Mice from each group were sacrificed 19-21 days after transplantation and pooled spleen cells (0.5 × 10⁶) were transferred into non irradiated B6 Rag mice. (A). Representative dot plot depicting the percentage of IL-17 and/or IFN-γ-secreting cells within the gated CD4⁺ T cell population obtained from the spleen, liver or colons of mice 60-65 days after transfer of spleen cells from B6→Balb/c or IL-17^−/−→Balb/c chimeras. (B,C). Individual spleens, liver and colon tissue from B6 Rag mice that received adoptive transfer of spleen cells from B6→Balb/c (■) or IL-17^−/−→Balb/c (□) chimeras (n=2-4/group) were pooled and the percentage (panel B) and absolute number (panel C) of CD4⁺ T cells secreting IFN-γ in each organ is depicted. Data are the cumulative results from three independent experiments. Each experiment had the same number of mice per group. (D). Individual spleens, livers and colon tissue from B6 Rag mice that received adoptive transfer of spleen cells from B6→Balb/c or IL-17^−/−→Balb/c chimeras (n=2-4/group) were pooled and the percentage of CD4⁺ T cells secreting IL-17 in each organ is depicted. (E). Pathological damage in the colon, liver and lung of mice 60-65 days after adoptive transfer of spleen cells from B6→Balb/c (n=9) or IL-17^−/−→Balb/c (n=9) chimeras. Data are the cumulative results from three independent experiments. Data are presented as the mean ± SEM. Statistics: * p ≤ 0.05.