Direct binding of NKp46-Ig and NKp44-Ig to HA. ELISA plates were coated with 0.1 μg HA rosettes followed by incubation with 0.5 μg, 0.2 μg, and 0.1 μg of the relevant fusion protein, as indicated. Bound proteins were detected using AP-conjugated secondary mAb. The data in the figure represent optical density (OD) absorbance (405 nm). Figure shows one representative experiment of 3 performed. Error bars indicate SD.