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: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: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. '
Project description:Generating durable humoral immunity through vaccination depends upon effective interaction of follicular helper T cells (Tfh) with germinal center (GC) B cells. Th1 polarization of Tfh cells is an important process shaping the success of Tfh-GC B cell interactions by influencing co-stimulatory and cytokine-dependent Tfh help to B cells. However, the question remains whether adjuvant-dependent modulation of Tfh cells enhances HIV-1 vaccine-induced anti-Envelope (Env) antibody responses. We investigated whether an HIV-1 vaccine platform designed to increase the number of Th1-polarized Tfh cells enhances the magnitude and quality of anti-Env antibodies. Utilizing a novel interferon-induced protein (IP)-10-adjuvanted HIV-1 DNA prime, followed by an MPLA+QS-21-adjuvanted Env protein boost in macaques (DIP-10 PALFQ), we observed higher anti-Env serum IgG titers with greater cross-clade reactivity, specificity to V1V2, and effector functions when compared to macaques primed with DNA lacking IP-10 and boosted with MPLA+alum-adjuvanted Env protein (DPALFA) The DIP-10 PALFQ vaccine regimen elicited higher anti-Env IgG1 and lower IgG4 antibodies in serum, showing for the first time that adjuvants can dramatically impact the IgG subclass profile in macaques. The DIP-10 PALFQ regimen also increased vaginal and rectal IgA antibodies to a greater extent. Within lymph nodes, we observed augmented GC B cell responses and promotion of Th1 gene expression profiles in GC Tfh cells. The frequency of GC Tfh cells correlated with both the magnitude and avidity of anti-Env serum IgG. Together, these data suggest that adjuvant-induced stimulation of Th1-Tfh cells is an effective strategy for enhancing the magnitude and quality of anti-Env antibody response.