miR-155 modulates chemokine receptor expression and migration of allogeneic donor T cells. On days 4 and 21 after BMT, splenocytes were harvested from F1 recipients and H2Kd- CD4⁺/CD8⁺ donor cells were analyzed by flow cytometry for chemokine receptor expression. Chemokine receptor expression was quantified by measuring mean fluorescence intensity (MFI). P values < .05 were considered significant. n = at least 5 mice per group at each time point. (A) Expression of CXCR4 on CD4⁺ and CD8⁺ WT and miR-155^−/− donor T cells on day 21 after transplantation. (B) Expression of S1P1 on CD4⁺ WT and miR-155^−/− donor T cells on day 21 after transplantation. (C) Expression of CCR5 on CD4⁺ and CD8⁺ WT and miR-155^−/− donor T cells on day 21 after transplantation. (D) Average IL-12Rb1 mRNA expression in untouched T cells isolated from spleens of recipient mice on day 21 after transplantation by RT-PCR. The results shown represent the average of 9 independent mouse samples performed each in triplicate. Values are expressed as relative expression after 2ΔCt calculations and normalization with 18s RNA. Bars represent SD. (E) Average STAT-4 mRNA expression in untouched T cells isolated from spleens of recipient mice on day 21 after transplantation by RT-PCR. (F) Average IFN-γ mRNA expression in untouched T cells isolated from spleens of recipient mice on day 21 after transplantation by RT-PCR. (G) Average CCR5 mRNA expression in untouched T cells isolated from spleens of recipient mice on day 21 after transplantation by RT-PCR.