Dose-response of migration of HEK 293 cells expressing WT or mutated CXCR3 receptors toward CXCL11. Migration was performed as described in “Materials and methods” in response to various concentrations of CXCL11 (ng/mL). (A) WT CXCR3. (B) 349stopΔ20 C-tail truncated. (C) 332stopΔ37 C-tail truncated. (D) 332-334L→A C-tail mutations. (E) S245 to A 3i loop mutation. (F) Double-mutant of 332stopΔ37 C-tail truncated and S245 to A 3i loop mutation. A representative experiment of at least 3 performed is presented. Each value represents the mean ± SD of triplicates of the representative experiment. ANOVA was used to determine the levels of difference between CXCL11 concentrations of 50, 100, 500, and 1000 ng/mL within each CXCR3 type. The differences in number of cells per high-power field (HPF) were statistically significant for all CXCR3 types except for D37/S245A. Therefore, multiple comparisons of number of cells per HPF between these concentrations in each receptor type were done by the Newman-Keuls test. For WT CXCR3, number of cells per HPF at 50 and 100 ng/mL were not statistically different. For the mutant 332-334L→A, number of cells/HPF at 50 versus 100 ng/mL and at 500 versus 1000 ng/mL were not statistically different, but these pairs of concentrations were statistically different from each other. For the mutant S245A, number of cells per HPF at 50 versus 100 ng/mL and 500 versus 100 ng/mL were statistically different. ANOVA also showed that the differences in number of cells per HPF were statistically significant for all CXCR3 types at 50 ng/mL CXCL11. Multiple comparisons of each mutant with WT CXCR3 at this concentration were performed by the Dunnett test. Except for S245A, all other mutants were different and statistically significant from the WT.