In summary, our data identify Th2-cell differentiation patterns linked to partial DC maturation stages with quantitative differences between pathogen-derived, TLR-dependent VSG antigens, and non-TLR-dependent TNF stimulation in vitro. No induction of FoxP3+ Treg cells could be observed by
any of our DCs in the absence of exogenous TGF-β in vitro. To assess how these DC maturation signatures prime T-cell responses in vivo, we injected differentially matured and OVA-loaded DCs together with OVA-specific TCR-transgenic OT-II T cells i.v. and determined proliferation and cytokine production Alectinib manufacturer of injected T cells. DCs matured with TNF, mfVSG, or MiTat1.5 sVSG all induced proliferation of CFSE-labeled T cells (Fig. 4A). The most profound priming in T cells was detected upon injection of LPS-matured DCs as determined by flow cytometry (Fig. 4A) or calculated as the division index (Fig. 4B). Furthermore, one single injection of DCs conditioned with TNF, mfVSG, or MiTat1.5 sVSG increased intracellular IL-13 and IL-5 release by ex vivo restimulated OVA-TCR-specific T cells (Fig. 4C and D), in contrast to mice which received LPS-matured
DCs which showed only background levels of IL-13- or IL-5-producing OVA-TCR-specific T cells (Fig. 4C this website and D). Similar to our in vitro findings (Supporting Information Fig. 4B), a low frequency of IFN-γ-releasing T cells was detectable after a single injection, irrespective of the DC maturation regimen. Clearly polarized Th1-cell responses resulted only after injection of LPS-matured
DCs (data not shown and Fig. 4C and D). Furthermore, injection of DC conditioned with TNF, mfVSG, or MiTat1.5 sVSG did not raise the frequency or total cellular amounts of FoxP3+ Treg cells among OVA-TCR-specific T cells in vivo similar to LPS-matured DCs (Supporting Information Fig. 5B and C) further strengthening the observation that partially mature DCs efficiently induce proliferation and priming of (CFSE labeled) OVA-TCR-specific T cells in vivo (Fig. 4A). Together, DCs conditioned by TNF- Bay 11-7085 or T. brucei-derived VSG antigens induce profound and comparable Th2-cell priming in vivo. Asthma induced by alum-guided immunization of mice with OVA is a widely used model for a Th2-cell mediated disease characterized by proinflammatory lung infiltrates of eosinophilic granulocytes and a subsequent Th2-cell dependent production of OVA-specific IgG1 and IgE 42. Mice subjected to repeated sensitization and antigen challenges showed a profound influx of total cells, in particular eosinophils in the bronchoalveolar lavage (BAL) as a major parameter for asthma (Fig. 5A). Three repetitive injections of OVA-loaded TNF, mfVSG, or MiTat1.5 sVSG-matured DCs did not change the total cellular influx in the lungs compared with noninjected animals.