Absence of RORγt/T-bet of donor T cells is associated with a distinct pattern of chemokine expression. (A) The absolute number of H-2^b+CD4⁺ T and H-2^b+CD8⁺ T cells in spleen, liver, and lung of recipients given WT, T-bet^−/−, RORγt^−/−, or RORγt^−/−/T-bet^−/− T cells donor cells 14 days after HCT. Mean ± SE is shown (n = 9), and data are from combined 3 replicate experiments. (B) Five days after BMT, splenocytes from recipients were stained for H-2K^b, CD4, and chemokine receptors. Gated H-2K^b+CD4⁺ T cells are shown in CD4 versus chemokine receptors. The expression profile of chemokine receptors on CD8⁺ T cells was similar to that of CD4⁺ T cells (data not shown). (C) Summary of the expression of chemokine receptors on CD4⁺ T cells. Representative 1 of 3 replicate experiments is shown. Asterisk indicates statistical significance: *P < .05; **P < .01; ***P < .001.