Intestinal dendritic cells in the pathogenesis of inflammatory bowel disease

Table 1 Intestinal dendritic cell subsets and other mononuclear phagocytes described to date

Subset	Anatomic location	Function, if known	Ref.
CD11chiCD11b+CD8α-	Peyer’s patches	Localized in the subepithelial dome	[57]
CD11chiCD11b+CD8α+		Localized in the interfollicular regions	[57]
CD11c+CD11b-CD8α-		Localized in both subepithelial dome and interfollicular regions; secretion of IL-10 in response to CD40 cross-linking; induction of T-cell release of IL-4/IL-10; promotion of T-cell proliferation	[58]
CD11cmid plasmacytoid DC
CD11c+CD11b+CD8α+ DC	Small-intestinal and colonic lamina propria	Low T-cell responses in vitro; IL-12p40lowIL-10+; tolerance to OVA (m); secretion of IFN-α; differentiation of Tr1-like cells that secrete IL-10, IL-4 and IFN-γ	[30,55]
CX3CR1+ DC		Pro-inflammatory activity dependent upon TNF-α production	[101]
CD11chiclass IIhiCD103+ DC		Generation of CCR9+α4β7+ T cells with gut tropism	[51]
CD11b+CD8α-CD103+/- DC	Mesenteric lymph node	Conversion of Foxp3- T cells to Foxp3+ T cells; retinoic acid and TGF-β required	[54]
CD11cloB220+CD8α+		Promotion of CD4+CD25+ Treg function; differentiation of Tr1-like cells (IL-10+IL-4+IFN-γ+) from naïve T cells after repeated stimulations
CD11chiCD11b+CD8α+		See above
CD11chiCD11b-CD8α-		See above
CD103+ DC		~50% of CD11c+ DC in the MLN; conversion of naïve T cells into Treg cells; retinoic acid and TGF-β required; induction of CCR9 on gut-tropic T cells	[16]
CD103- DC		Expression of pro-inflammatory cytokines (TNF-α, IL-6, IL-23p19) and genes such as Tbet, tlr2 and tbx21	[16]
CD11chiclass IIhiCD103+ DC		Induction of CCR9 gut-homing receptor on CD4+ T cells	[53]
CD11b+CD11c- macrophages	Small and large intestine	Induction of Treg cells, secretion of IL-10 but not IL-12p40 or IL-12p70	[105,106]

DC: Dendritic cell; OVA: Ovalbumin; IFN: Interferon; MLN: Mesenteric lymph node; Tr1: Type 1 Treg cells; TGF: Transforming growth factor; IL: Interleukin; M: Mouse studies.