Figure 5. IL-2 and IL-27 synergistically induce IL-10 production by both murine and human CTL.

(a, b) CFSE labeled CD8⁺ CL-4 cells were stimulated with influenza-infected DC in the presence or absence of CD4⁺ TS-1 cells for 4d. The cultured cells were treated with indicated conditions. Then the production of IL-10 and IFN-γ by CL-4 cells were measured through ICS. (b) The MFI of IL-10 in IL-10⁺ cells is depicted. (c) WT mice were infected with influenza and various cell types of the infected lungs were sorted out as described in methods. The expression of IL-27 EBI-3 and p28 subunits was measured through quantitative RT-PCR. (d) WT mice were injected with Rat IgG or α-CD4 Ab and infected with influenza. At d6 p.i., the levels of IL-27 p28 in BALF were measured through ELISA. (e) Purified human CD8⁺ T cells were stimulated with α-CD3 plus α-CD28 with indicated conditions for 3d. Then the levels of IL-10 in the medium were measured by ELISA. Numbers are the percentages of cells in gated population. (a-d) Data are representative of at least three separate experiments. (e) Data are representative of at least two separate experiments employing an additional donor.