Project description:In this study, we generated a chimeric situation by injection of different gene-modified BM-DCs into different strains of gene-modified recipient mice. This allowed us to identify the separate functional contributions of injected versus endogenous DCs for Th1 polarization. We identified the cellular source of IL-12p70 production after subcutaneous BM-DC vaccination as endogenous migratory XCR1+ bystander DCs in the skin draining lymph nodes. DC-DC and DCT cell interaction studies revealed a time course of Th0 priming by injected BM-DCs, followed by interactions of BM-DC with the IL-12+ XCR1+ bystander DCs, and finally IL-12+ XCR1+ bystander DC interactions for Th1 induction. Transcriptional profiling of the bystander DCs underscores their Th1 polarization potential. Together, this study shows that DC-vaccination requires the bystander activation of endogenous DCs for Th1 priming. Our data also challenge the general concept of Th1 priming by a single DC providing all signals 1, 2 and 3 to T cells for Th1 polarization.
Project description:Success of DC vaccines relies on the quality of antigen presentation, costimulation, lymph node migration, and the release of IL-12, in case of Th1 priming. Here, we provide evidence for interaction between the injected vaccine DCs with endogenous lymph node-resident DCs for Th1 induction. While migration of the injected DCs was essential for antigen delivery to the lymph node, the injected DCs contributed only partially to Th0 priming and were unable to instruct Th1 generation. Instead, we provide evidence that the lymph node-resident XCR1+ DCs are activated by the injected DCs to present the cognate antigen and release IL-12 for Th1 polarization. The timing of interactions in the draining lymph nodes appeared step-wise as (a) injected DCs with cognate T cells, (b) injected DCs with bystander DCs, and (c) bystander DCs with T cells. The transcriptome of the bystander DCs showed a downregulation of Treg- and Th2/Th9-inducing genes and self-antigen presentation, as well as upregulation of MHC class II and genes required for Th1 instruction. Together, these data show that injected mature lymph node migratory DCs direct T cell priming and bystander DC activation, but not Th1 polarization, which is mediated by endogenous IL-12p70+XCR1+ resident bystander DCs. Our results are of importance for clinical DC-based vaccinations against tumors where endogenous DCs may be functionally impaired by chemotherapy.
Project description:The functional diversification of dendritic cells (DCs) is a key step in establishing protective immune responses. Despite the importance of this lineage diversity, its genetic basis is not fully understood. DC-SCRIPT (Zfp366) is a poorly known transcription factor expressed in conventional DCs (cDCs) and their committed bone marrow progenitors but not in plasmacytoid DCs (pDCs). We show that mice lacking DC-SCRIPT displayed substantially impaired development of IRF8-dependent conventional DC1 (cDC1), while cDC2 differentiated normally. The residual DC-SCRIPT-deficient cDC1s had impaired CD8+ T-cell cross-priming, which could be in part explained by the direct control of DC-SCRIPT on IL-12p40 production. Genome-wide mapping of DC-SCRIPT binding and gene expression analyses revealed a key role for DC-SCRIPT in maintaining cDC1 identity via the direct regulation of cDC1 signature genes, including Irf8. Our study reveals DC-SCRIPT to be a critical component of the gene regulatory program shaping the functional attributes of cDC1s.
Project description:The functional diversification of dendritic cells (DCs) is a key step in establishing protective immune responses. Despite the importance of this lineage diversity, its genetic basis is not fully understood. DC-SCRIPT (Zfp366) is a poorly known transcription factor expressed in conventional DCs (cDCs) and their committed bone marrow progenitors but not in plasmacytoid DCs (pDCs). We show that mice lacking DC-SCRIPT displayed substantially impaired development of IRF8-dependent conventional DC1 (cDC1), while cDC2 differentiated normally. The residual DC-SCRIPT-deficient cDC1s had impaired CD8+ T-cell cross-priming, which could be in part explained by the direct control of DC-SCRIPT on IL-12p40 production. Genome-wide mapping of DC-SCRIPT binding and gene expression analyses revealed a key role for DC-SCRIPT in maintaining cDC1 identity via the direct regulation of cDC1 signature genes, including Irf8. Our study reveals DC-SCRIPT to be a critical component of the gene regulatory program shaping the functional attributes of cDC1s.
Project description:Purpose:gene discrepancy analysis and signaling pathway of tumor tissues in the PBS, Taraxasterol, DC tumor vaccine and Taraxasterol combined with DC tumor vaccine group
Project description:The functional diversification of dendritic cells (DCs) is a key step in establishing protective immune responses. Despite the importance of this lineage diversity, its genetic basis is not fully understood. DC-SCRIPT (Zfp366) is a poorly known transcription factor expressed in conventional DCs (cDCs) and their committed bone marrow progenitors but not in plasmacytoid DCs (pDCs). We show that mice lacking DC-SCRIPT displayed substantially impaired development of IRF8-dependent conventional DC1 (cDC1), while cDC2 differentiated normally. The residual DC-SCRIPT-deficient cDC1s had impaired CD8+ T-cell cross-priming, which could be in part explained by the direct control of DC-SCRIPT on IL-12p40 production. Genome-wide mapping of DC-SCRIPT binding and gene expression analyses revealed a key role for DC-SCRIPT in maintaining cDC1 identity via the direct regulation of cDC1 signature genes, including Irf8. Our study reveals DC-SCRIPT to be a critical component of the gene regulatory program shaping the functional attributes of cDC1s. This SuperSeries is composed of the SubSeries listed below.
Project description:We have shown that DC vaccine is superior to peptide vaccine in terms of priming and expansion of antigen-specific CD8+ T cells. DC vaccine-primed pmel-1 cells displayed better effecter functions than cells by peptide-primed cells in terms of cytokine production and externalization of cytotoxic granules. Furthermore DC vaccine-primed cells were metabolically distinct from peptide-primed cells. To confirm these findings, we performed a microarray analysis using splenic pmel-1 T cells from mice immunized with hgp100 peptide vaccine or DC vaccine. We also used splenic naïve pmel-1 T cells as a control.
Project description:Results from the Step trial in humans and studies in non-human primates highlighted a role for heightened activated CD4 T cell response in promoting HIV/SIV acquisition. However, the contribution of vaccine-specific CD4 T cell response in influencing protection is not known. Here, using the macaque model, we show that vaccine-induced Th1-biased CCR5+ CD4 T cell response in blood and mucosal tissue above a certain thresh¬old is detrimental for vaccine-mediated protection against pathogenic mucosal SIV infections.
Project description:Human immune cell subsets develop in immunodeficient mice following reconstitution with human CD34+ haematopoietic stem cells. These “humanized” mice are useful models to study human immunology and human-tropic infections, autoimmunity and cancer. However, some human immune cell subsets are unable to fully develop or acquire full functional capacity due to a lack of cross-reactivity of many growth factors and cytokines between species. “Classical” (c) DC arise from a separate precursor to monocytes and initiate and direct T cell responses. In mice they can be further categorized into cDC1, which mediate Th1 and CD8+ T cell responses, and cDC2, which mediate Th2 and Th17 responses. The gene expression profiles and phenotype human CD141+ DC and CD1c+ DC subsets align with mouse cDC1 and cDC2 respectively but there are also key interspecies differences. Human CD141+ DC and CD1c+ DC develop in humanized mice but the extent to which they resemble their human blood counterparts is not yet known. We therefore analyzed the gene expression profiles of CD141+ DC and CD1c+ DC in humanized mice and demonstrated that they closely resemble those in human blood, making this an attractive model in which to study human DC in vitro or on vivo. We further used this model to explore changes in DC subsets after activation with TLR3 and TLR7/8 ligands, poly I:C and R848 in vivo. A core panel of genes consistent with DC maturation status were upregulated by both subsets. R848 specifically upregulated genes associated with Th17 responses by CD1c+ DC, whilst poly I:C upregulated IFN-λ genes specifically by CD141+ DC. Thus CD141+ DC and CD1c+ DC share a similar activation profiles in vivo but also have induce unique signatures that support specialized roles in CD8+ T cell priming and Th17 responses respectively. '