Figure 4. Monocyte origin of DC-SIGN⁺ Mo-DCs.

(A) CD45.2⁺ marrow monocytes were transferred i.v. into CD45.1⁺ hosts. 24 h later, PBS or 5 μg of LPS was injected i.v. with 10 μg Alexa647-MMD3 α-DC-SIGN and 24 h later, DC-SIGN⁺ CD206⁺ DCs of CD45.2 origin were enumerated. One of 3 similar experiments. (B) WT and LysMCre×iDTR mice were injected with DT and 12 h later, blood monocytes (Ly6G⁻ CD115⁺ CD11b⁺ Ly6C^hi/^lo) were analyzed (left panels). 24 h after DT, 5 μg of LPS plus 10 μg of MMD3-Alexa 647 mAb were given i.v. and 12 h later, skin draining lymph node cells were analyzed as CD19/CD3/NK1.1⁻ and CD11c ^high and segregated into 3 DC populations (right) to look for DC-SIGN⁺ Mo-DCs (arrow). (C) Lymph node sections were stained for Mo-DCs with α-DC-SIGN (BMD10, green), resident DCs with α-DEC-205 (NLDC145, red), and B cells with α-B220 (blue) at 100×. (D) WT and Flt3^−/− mice were injected with 5 μg of LPS and 10 μg of MMD3-Alexa 647 α-DC SIGN mAb to enumerate Mo-DCs expressing DC-SIGN (blue) or MMR/CD206 (red) 24h later. Cells/10⁶ lymph node cells from two independent experiments with 2 mice/group.