Flow cytometric analysis of cytokine production by donor T cells in spleen and liver.

(A) Dot plots of intracellular cytokine staining from aGVHD mouse spleen and livers. Samples are gated on Thy1.2⁺ and EMA-negative (ie, live) cells. The percentage of positive cells is given in each quadrant. (B,C) Graphs show the means and SDs of the percentages of cytokine-positive cells as determined in A. (B) IL-2-tk spleen cell recipients treated with PBS (n = 10, solid bars) or GCV (n = 10, hatched bars) are compared. Notice that GCV treatment significantly decreased the percentage of IFN-γ–positive cells in the spleen and the percentage of IL-2–positive cells in both organs (P < .05, indicated by asterisk). However, no significant effect on IL-4–positive cells was observed. (C) Graphs show the significant decrease of IL-4–positive cells in the liver of IL-4-tk spleen cell recipients treated with GCV (n = 10) in comparison with the PBS group (n = 9). No other cytokine-positive population was affected in either organ.