Browsing by Subject "Dendritic cells"
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Item An IL-23-STAT4 pathway is required for the proinflammatory function of classical dendritic cells during CNS inflammation(National Academy of Sciences, 2024) Alakhras, Nada S.; Zhang, Wenwu; Barros, Nicolas; Sharma, Anchal; Ropa, James; Priya, Raj; Yang, X. Frank; Kaplan, Mark H.; Biochemistry and Molecular Biology, School of MedicineAlthough many cytokine pathways are important for dendritic cell (DC) development, it is less clear what cytokine signals promote the function of mature dendritic cells. The signal transducer and activator of transcription 4 (STAT4) promotes protective immunity and autoimmunity downstream of proinflammatory cytokines including IL-12 and IL-23. In experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), Stat4-/- mice are resistant to the development of inflammation and paralysis. To define whether STAT4 is required for intrinsic signaling in mature DC function, we used conditional mutant mice in the EAE model. Deficiency of STAT4 in CD11c-expressing cells resulted in decreased T cell priming and inflammation in the central nervous system. EAE susceptibility was recovered following adoptive transfer of wild-type bone marrow-derived DCs to mice with STAT4-deficient DCs, but not adoptive transfer of STAT4- or IL-23R-deficient DCs. Single-cell RNA-sequencing (RNA-seq) identified STAT4-dependent genes in DC subsets that paralleled a signature in MS patient DCs. Together, these data define an IL-23-STAT4 pathway in DCs that is key to DC function during inflammatory disease.Item Catching Our Breath: Updates on the Role of Dendritic Cell Subsets in Asthma(Wiley, 2023) Lajiness, Jacquelyn D.; Cook-Mills, Joan M.; Pediatrics, School of MedicineDendritic cells (DCs), as potent antigen presenting cells, are known to play a central role in the pathophysiology of asthma. The understanding of DC biology has evolved over the years to include multiple subsets of DCs with distinct functions in the initiation and maintenance of asthma. Furthermore, asthma is increasingly recognized as a heterogeneous disease with potentially diverse underlying mechanisms. The goal of this review is to summarize the role of DCs and the various subsets therein in the pathophysiology of asthma and highlight some of the crucial animal models shaping the field today. Potential future avenues of investigation to address existing gaps in knowledge are discussed.Item Cell-surface Milieu Remodeling in Human Dendritic Cell Activation(The American Association of Immunologists, 2024) Udeshi, Namrata D.; Xu, Charles; Jiang, Zuzhi; Gao, Shihong Max; Yin, Qian; Luo, Wei; Carr, Steven A.; Davis, Mark M.; Li, Jiefu; Microbiology and Immunology, School of MedicineDendritic cells (DCs) are specialized sentinel and APCs coordinating innate and adaptive immunity. Through proteins on their cell surface, DCs sense changes in the environment, internalize pathogens, present processed Ags, and communicate with other immune cells. By combining chemical labeling and quantitative mass spectrometry, we systematically profiled and compared the cell-surface proteomes of human primary conventional DCs (cDCs) in their resting and activated states. TLR activation by a lipopeptide globally reshaped the cell-surface proteome of cDCs, with >100 proteins upregulated or downregulated. By simultaneously elevating positive regulators and reducing inhibitory signals across multiple protein families, the remodeling creates a cell-surface milieu promoting immune responses. Still, cDCs maintain the stimulatory-to-inhibitory balance by leveraging a distinct set of inhibitory molecules. This analysis thus uncovers the molecular complexity and plasticity of the cDC cell surface and provides a roadmap for understanding cDC activation and signaling.Item Cord blood sphingolipids are associated with atopic dermatitis and wheeze in the first year of life(Elsevier, 2022) Hoji, Aki; Kumar, Rajesh; Gern, James E.; Bendixsen, Casper G.; Seroogy, Christine M.; Cook-Mills, Joan M.; Pediatrics, School of MedicineBackground: Allergen-sensitized pregnant mice have increased plasma levels of the lipids β-glucosylceramides (βGlcCers) that are transplacentally transferred to the fetus, increased subsets of proinflammatory dendritic cells in the fetal liver and pup lung, and increased allergen-induced offspring lung inflammation. Objective: Our aim was to determine whether these preclinical observations extend to a human association of βGlcCers with wheeze and allergic disease in the prospective Wisconsin Infant Study Cohort. Methods: We measured 74 lipids in cord blood plasma by using mass spectrometry detection of sphingolipids, eicosanoids, and docosinoids, as well as an ELISA for 13-hydroxyoctadecadienoic acid. Lipid profiles were determined by unbiased Uniform Manifold Approximation and Projection dimensional reduction machine learning. Lipid profiles and a proinflammatory lipid index were analyzed for association with maternal allergy and childhood outcomes of wheeze, atopic dermatitis, cord blood leukocytes, and total IgE level at age 1 year. Results: Uniform Manifold Approximation and Projection analysis of lipids defined 8 cluster-specific plasma lipid profiles. Cluster 6 had significantly lower levels of plasma βGlcCers and a higher frequency of cord blood plasmacytoid dendritic cells that mediate anti-inflammatory responses, which is consistent with an anti-inflammatory profile. For clusters and for each infant, a proinflammatory lipid index was calculated to reflect the sum of the proinflammatory lipids minus the anti-inflammatory lipids that were significantly different than in cluster 6. The cluster proinflammatory lipid index was associated with cord blood basophil frequency and with wheeze and atopic dermatitis in the first year of life. The infant inflammatory lipid index was associated with increased risk of wheeze in the first year of life. Conclusion: The cord blood proinflammatory lipid index is associated with early-life atopic dermatitis and wheezing.Item Dendritic Cell Therapy in Transplantation, Phenotype Governs Destination and Function(Lippincott, Williams & Wilkins, 2018-10) Samy, Kannan P.; Brennan, Todd V.; Surgery, School of MedicineItem Did Dendritic Cell Activation, Induced by Adenovirus-Antibody Complexes, Play a Role in the Death of Jesse Gelsinger?(Elsevier, 2020-03-04) Baker, Andrew H.; Herzog, Roland W.; Pediatrics, School of MedicineItem Effect of CpG Depletion of Vector Genome on CD8+ T Cell Responses in AAV Gene Therapy(Frontiers Media, 2021-05-31) Bertolini, Thais B.; Shirley, Jamie L.; Zolotukhin, Irene; Li, Xin; Kaisho, Tsuneyasu; Xiao, Weidong; Kumar, Sandeep R.P.; Herzog, Roland W.; Pediatrics, School of MedicineAdeno associated viral (AAV) vectors have emerged as a preferred platform for in vivo gene replacement therapy and represent one of the most promising strategies to treat monogenetic disorders such as hemophilia. However, immune responses to gene transfer have hampered human gene therapy in clinical trials. Over the past decade, it has become clear that innate immune recognition provides signals for the induction of antigen-specific responses against vector or transgene product. In particular, TLR9 recognition of the vector's DNA genome in plasmacytoid dendritic cells (pDCs) has been identified as a key factor. Data from clinical trials and pre-clinical studies implement CpG motifs in the vector genome as drivers of immune responses, especially of CD8+ T cell activation. Here, we demonstrate that cross-priming of AAV capsid-specific CD8+ T cells depends on XCR1+ dendritic cells (which are likely the main cross-presenting cell that cooperates with pDCs to activate CD8+ T cells) and can be minimized by the elimination of CpG motifs in the vector genome. Further, a CpG-depleted vector expressing human coagulation factor IX showed markedly reduced (albeit not entirely eliminated) CD8+ T cell infiltration upon intramuscular gene transfer in hemophilia B mice when compared to conventional CpG+ vector (comprised of native sequences), resulting in better preservation of transduced muscle fibers. Therefore, this deimmunization strategy is helpful in reducing the potential for CD8+ T cell responses to capsid or transgene product. However, CpG depletion had minimal effects on antibody responses against capsid or transgene product, which appear to be largely independent of CpG motifs.Item Forming a Complex with MHC Class I Molecules Interferes with Mouse CD1d Functional Expression(Public Library of Science, 2013-08-29) Gourapura, Renukaradhya J.; Khan, Masood A.; Gallo, Richard M.; Shaji, Daniel; Liu, Jianyun; Brutkiewicz, Randy R.; Microbiology and Immunology, School of MedicineCD1d molecules are structurally similar to MHC class I, but present lipid antigens as opposed to peptides. Here, we show that MHC class I molecules physically associate with (and regulate the functional expression of) mouse CD1d on the surface of cells. Low pH (3.0) acid stripping of MHC class I molecules resulted in increased surface expression of murine CD1d on antigen presenting cells as well as augmented CD1d-mediated antigen presentation to NKT cells. Consistent with the above results, TAP1-/- mice were found to have a higher percentage of type I NKT cells as compared to wild type mice. Moreover, bone marrow-derived dendritic cells from TAP1-/- mice showed increased antigen presentation by CD1d compared to wild type mice. Together, these results suggest that MHC class I molecules can regulate NKT cell function, in part, by masking CD1d.Item Intestinal dendritic cells, gatekeepers preventing ethanol-induced liver disease(Wolters Kluwer, 2023) Llorente, Cristina; Rungratanawanich, Wiramon; Liangpunsakul, Suthat; Medicine, School of MedicineItem Negative regulation of TLR signaling in myeloid cells--implications for autoimmune diseases(Wiley, 2016-01) Hamerman, Jessica A.; Pottle, Jessica; Ni, Minjian; He, Yantao; Zhang, Zhong-Yin; Buckner, Jane H.; Department of Biochemistry & Molecular Biology, IU School of MedicineToll-like receptors (TLR) are transmembrane pattern recognition receptors that recognize microbial ligands and signal for production of inflammatory cytokines and type I interferon in macrophages and dendritic cells (DC). Whereas TLR-induced inflammatory mediators are required for pathogen clearance, many are toxic to the host and can cause pathological inflammation when over-produced. This is demonstrated by the role of TLR-induced cytokines in autoimmune diseases, such as rheumatoid arthritis, inflammatory bowel disease, and systemic lupus erythematosus. Because of the potent effects of TLR-induced cytokines, we have diverse mechanisms to dampen TLR signaling. Here, we highlight three pathways that participate in inhibition of TLR responses in macrophages and DC, and their implications in autoimmunity; A20, encoded by the TNFAIP3 gene, Lyp encoded by the PTPN22 gene, and the BCAP/PI3K pathway. We present new findings that Lyp promotes TLR responses in primary human monocytes and that the autoimmunity risk Lyp620W variant is more effective at promoting TLR-induced interleukin-6 than the non-risk Lyp620R protein. This suggests that Lyp serves to downregulate a TLR inhibitory pathway in monocytes, and we propose that Lyp inhibits the TREM2/DAP12 inhibitory pathway. Overall, these pathways demonstrate distinct mechanisms of negative regulation of TLR responses, and all impact autoimmune disease pathogenesis and treatment.