Background & Aims Immune responses in the intestine are controlled by regulatory T cells (Treg cells), which prevent inflammation in response to commensal bacteria. v subunit was measured in purified subpopulations of DCs by quantitative PCR and immunoblot analyses. Results In vitro, CD103+ DCs generated more Treg cells in the presence of latent TGF- than other MLN DCs. Efficient generation of Treg cells required expression of the integrin v subunit by DCs; mice that lacked v in immune cells did not convert na?ve T cells to intestinal Treg cells in response to oral antigen. CD103+ DCs derived from the MLNs selectively expressed high levels of integrin v8, compared with other populations of DCs. Conclusions Expression of v8 is required for CD103+ DCs to become specialized and activate latent TGF- and generate Treg cells during the induction of tolerance to intestinal antigens in mice. and co-culture than their CD103? counterparts (Physique 1A). This is reliant on TGF- as TGF- blocking antibodies prevented Treg generation by both CD103+ and CD103 completely? DCs (Body 1A). FoxP3 induction was also considerably impaired when DCs and T cells had been cultured in serum free of charge moderate (Body 1BCC), despite equivalent T cell proliferation compared to that observed in serum-replete moderate (data not proven), indicating that most TGF- in charge of Treg era was produced from serum in the lifestyle moderate, than endogenous production by DCs or T cells rather. However, it really is worthy of noting that in serum-free circumstances also, Compact disc103+ DCs from control mice created even more Tregs than Compact disc103? DCs (Body 1C). Open up in another window Body 1 Compact disc103+ DCs promote Treg era in the current presence of latent TGF-Na?ve Compact disc4+ FoxP3? T cells were cultured with FACS-sorted Compact disc103 and Compact disc103+? DCs from MLNs in the current presence of anti-CD3. The percentage of FoxP3+ T cells generated was assessed after 5 times by FACS. (A) Cells were cultured in medium made up of 10% fetal calf serum and anti-CD3, with or without the addition of neutralizing antibodies against TGF- (TGF- ab). (BCD) Cells were cultured in serum-free medium, with or without the addition of latent TGF- , active TGF- or RA as indicated. Representative FACS plots are shown in (B). Cells are gated on CD4+ cells, FoxP3 gates are indicated (gate position was set to give 0% positive cells in unstained samples). (C,D) show data from all samples in the same experiment. In all cases Alisertib cost data points show mean standard deviation of at least three individual DC: T cell cultures and similar results were seen in three (C) or two (D) impartial experiments. *, which confers on this DC subset the ability to synthesize and secrete RA, which promotes Treg generation 10, 11. Consistent with these studies, CD103+ and CD103? DCs produced comparative proportions of FoxP3+ Tregs Rabbit polyclonal to Cytokeratin 1 when cultured with active TGF- and RA (Physique 1D). However, addition of RA was not sufficient to allow CD103? DCs to efficiently generate Tregs in response to latent TGF-. Therefore, the increased induction of FoxP3+ Tregs by CD103+ Alisertib cost DCs was in part due to increased activation of latent TGF-, impartial of their ability to produce RA. Intestinal CD103+ DCs activate TGF- via v integrins v integrins are important physiological activators of latent TGF- and mice deficient in both v6 and v8, or lacking the integrin binding site in the latency-associated peptide (LAP), develop phenotypes closely resembling TGF- knockouts 12, Alisertib cost 13. We have previously reported that mice lacking v integrins in myeloid cells have reduced numbers of intestinal Tregs and develop spontaneous colitis, and that DCs.