CLEC4F is involved in the presentation of α-GalCer to NKT cells.

<p>(A) The schematic structure of α-GalCer. (B) The binding curves were obtained from the function of Fc.CLEC4F concentration and fluorescence intensity determined from array images. (C) Competition experiment between solution and surface for Fc.CLEC4F binding to α-GalCer and three derivatives. At different concentration of the competitors, binding curves were obtained from the bound Fc.CLEC4F concentration and fluorescence. (D) Secretion of IFN-γ and IL-4 of NKT cells after incubation of α-GalCer presented by Kupffer cells isolated from wild-type and <i>Clec4f−/−</i> mice. Kupffer cells (1×10<sup>5</sup> cells) isolated form wild-type and <i>Clec4f−/−</i> littermates were treated with serial concentration of α-GalCer (10, 30, 100, 300 and 1000 ng/ml) then co-cultured with NKT cells (1×10<sup>5</sup> cells). The supernatant were collected at 72 h post-stimulation and detected the IL-4 and IFN-γ production by ELISA. (E) Effect of CD1d-blocking antibody in the α-GalCer presentation by wild-type and <i>Clec4f−/−</i> Kupffer cells. Kupffer cells were pretreated with CD1d blocking antibody. Three hours later, α-GalCer (300 ng/ml) was added and co-cultured with NKT cells. The supernatant were collected at 72 h post-stimulation and detected the IL-4 and IFN-γ production by ELISA.</p>