Natural Killer Dendritic Cells Enhance Immune Responses Elicited by α-Galactosylceramide-Stimulated Natural Killer T Cells

Figure 1

NKDCs produce IFN-γ in the presence of NKT cells following α-GC stimulation. (a-b) Splenocytes isolated from B6 WT, CD1d KO, and Vα14 TCR Tg mice were stimulated with either PBS or α-GC (100 ng/mL) for 16 hours in vitro. (a) Intracellular IFN-γ production and surface CD69 expression were measured by flow cytometry in α-GC/CD1d dimer⁺-gated NKT cells (𝑛=3). (b) Intracellular IFN-γ production was assessed in NK cells (NK1.1⁺CD11c⁻TCRβ ⁻), NKDCs (NK1.1⁺CD11c⁺TCRβ ⁻), and DCs (NK1.1⁻CD11c⁺TCRβ ⁻) by flow cytometry. Top, representative FACS plots; bottom, summary. The mean values ± SD (𝑛=3, ^∗𝑃<0.05, ^∗∗𝑃<0.01) are shown. Representative data from two independent experiments are shown. (c) Either α-GC (2 μg) or PBS was i.p. injected into B6 WT mice. The intracellular expression of IFN-γ was measured in NK cells (NK1.1⁺CD11c⁻TCRβ ⁻), NKT cells (NK1.1⁺CD11c⁻TCRβ ⁺), NKDCs (NK1.1⁺CD11c⁺TCRβ ⁻), and DCs (NK1.1⁻CD11c⁺TCRβ ⁻) using flow cytometry at the indicated time points.