Figure 5. Ly6C^Hi-CD11c^Hi cells retain functional properties of monocytes.

A. Despite a large capacity for antigen capture, Ly6C^Hi-CD11c^Hi cells do not present the internalized antigen to T-cells, a feature similar to monocytes but in contrast to dendritic cells. Mice were treated with anti-CD40 and 40 later injected intravenously with 1mg OVA protein. 30 minutes after OVA injection splenocytes were harvested and Ly6C^Hi-CD11c^Hi cells, Ly6C^Hi monocytes, and CD11b^Hi-CD11c^Hi cDCs were isolated from the same spleen and separately co-cultured with CFSE-labeled OT-I or OT-II T-cells over a range of T-cell/DC ratios. After 60h, antigen presentation was assessed by flow cytometric analysis of CFSE0-dilution to measure T-cell proliferation. B. Distribution of cDC and monocyte in the spleen of untreated control mice vs. anti-CD40 treated mice. A significant portion of the cDCs (Ly6C^Neg-CD11c^Hi) are found in the T-cell zone after treatment with anti-CD40, while all Ly6C^Hi cells remain outside the white pulp. Data are representative of 3 independent experiments two mice per group.