Description:
<jats:title>Abstract</jats:title><jats:p>The CD11c<jats:sup>+</jats:sup> cell population in the non‐parenchymal cell population of the mouse liver contains dendritic cells (DC), NK cells, B cells and T cells. In the hepatic CD11c<jats:sup>+</jats:sup> DC population from immunocompetent or immunodeficient [recombinase‐activating gene‐1 (RAG1)<jats:sup>–/–</jats:sup>] C57BL/6 mice (rigorously depleted of T cells, B cells and NK cells), we identified a B220<jats:sup>+</jats:sup> CD11c<jats:sup>int</jats:sup> subset of ‘plasmacytoid’ DC, and a B220<jats:sup>–</jats:sup> CD11c<jats:sup>+</jats:sup> DC subset. The latter DC population could be subdivided into a major, immature (CD40<jats:sup>lo</jats:sup> CD80<jats:sup>lo</jats:sup> CD86<jats:sup>lo</jats:sup> MHC class II<jats:sup>lo</jats:sup>) CD11c<jats:sup>int</jats:sup> subset, and a minor, mature (CD40<jats:sup>hi</jats:sup> CD80<jats:sup>hi</jats:sup> CD86<jats:sup>hi</jats:sup> MHC class II<jats:sup>hi</jats:sup>) CD11c<jats:sup>hi</jats:sup> subset. Stimulated B220<jats:sup>+</jats:sup> but not B220<jats:sup>–</jats:sup> DC produced type I interferon. NKT cell activation <jats:italic>in vivo </jats:italic>increased the number of liver B220<jats:sup>–</jats:sup> DC three‐ to fourfold within 18 h post‐injection, and up‐regulated their surface expression of activation marker, while it contracted the B220<jats:sup>+</jats:sup> DC population. Early in virus infection, the hepatic B220<jats:sup>+</jats:sup> DC subset expanded, and both, the B220<jats:sup>+</jats:sup> as well as B220<jats:sup>–</jats:sup> DC populations in the liver matured. <jats:italic>In vitro</jats:italic>, B220<jats:sup>–</jats:sup> but not B220<jats:sup>+</jats:sup> DC primed CD4<jats:sup>+</jats:sup> or CD8<jats:sup>+</jats:sup>T cells. Expression of distinct marker profiles and functions, and distinct early reaction to activation signals hence identify two distinct B220<jats:sup>+</jats:sup> and B220<jats:sup>–</jats:sup> subsets in CD11c<jats:sup>+</jats:sup> DC populations freshly isolated from the mouse liver.</jats:p>