Analysis of chemokine receptor expression in the context of altered T-bet levels in primary CD4⁺ T cells. Real-time PCR analysis (A,C) and flow cytometric (B,D) surface staining of mRNA levels of CXCR3 in T cells activated under different polarizing conditions (mean ± SEM). (A-B) WT and T-bet^–/– CD4⁺ T cells. (C-D) WT and T-bet CD2-Tg CD4⁺ T cells. (E) Real-time PCR analysis of CXCR3 expression in primary T-bet^–/– and T-bet^–/– × IFN-γ^–/– CD4⁺ T cells retrovirally transduced with empty retrovirus (RV) or T-bet RV (mean ± SEM). (F) Flow cytometric surface staining of CXCR3 in retrovirally transduced T cells. (G) mRNA levels of CCR5 in WT and T-bet^–/– T cells. All real-time PCR results are normalized to β-actin and are expressed as mean ± SEM (*P < .01). Shaded areas represent isotype staining.