Ephrin-A1 stimulates migration. (A) SDF-1α chemotaxis assay with peripheral blood CD4⁺ T cells. Fc indicates control-Fc; A1, ephrin-A1-Fc; FcU, Fc only in the lower chamber; A1U, A1 only in the lower chamber; Fc SDF-1α and A1 SDF-1α, 100 ng/mL SDF-1α added to the lower chamber and Fc and A1 added to the transwell; and Fc SDF-1 O/U and A1 SDF-1 O/U, 100 ng/mL SDF-1α added to both the transwell and the lower chamber and Fc and A1 added to the transwell. Standard error of the mean (SEM) is shown for 4 different experiments. (B) Effect of FBS on ephrin-A1-induced chemotaxis. Different FBS concentrations (in %) were included in the media added to the transwell. One hundred nanograms per milliliter SDF-1α was added to the lower chamber. Fc indicates control-Fc (▪); and A1, ephrin-A1-Fc (▦). SEM is shown for 4 different experiments. (C) MIP3β chemotaxis assay. Fc indicates control-Fc; A1, ephrin-A1-Fc; Fc MIP3β and A1 MIP3β, 500 ng/mL MIP3β added to the lower chamber and Fc and A1 added to the transwell; and Fc MIP3β O/U and A1 MIP3β O/U, 500 ng/mL MIP3β added to both the transwell and the lower chamber and Fc and A1 added to the transwell. SEM is shown for 4 different experiments.