Compared with other lysophospholipid mediators such as sphingosine-1-phosphate and lysophosphatidic acid, little is known about the physiological significance of the related bioactive lysosphingolipid sphingosylphosphorylcholine (SPC), which is present in high-density lipoprotein particles. The present study was undertaken to evaluate the effect of SPC on human immature dendritic cells (DCs). Reverse transcription-polymerase chain reaction and flow cytometry assays revealed that DCs express two putative receptors for SPC, ovarian cancer G-protein-coupled receptor 1 and G-protein-coupled receptor 4. Exposure to SPC induced a rapid and transient increase in intracellular free calcium concentrations but did not stimulate endocytosis or chemotaxis of DCs. SPC increased the expression of HLA-DR, CD86 and CD83 and improved the T-cell priming ability of DCs, as well as the ability of DCs to stimulate the production of interferon-gamma by allogeneic peripheral blood mononuclear cells during the mixed lymphocyte reaction. Consistent with these results, we also observed that SPC stimulated the production of interleukin (IL)-12 and IL-18 by DCs. Taken together, our results support the notion that the accumulation of SPC in peripheral tissues during the course of inflammatory processes may favour the development of T helper type 1 immunity.
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http://dx.doi.org/10.1111/j.1365-2567.2007.02578.x | DOI Listing |
Acta Dermatovenerol Croat
November 2024
Prof. Miloš Nikolić, MD, PhD, University of Belgrade, School of Medicine,, Belgrade, Serbia;
Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a very rare and aggressive hematologic malignancy, arising from plasmacytoid dendritic cells (pDCs). BPDCN frequently has, at least initially, exclusively cutaneous presentation. We present a 45-year-old woman with a 3-month history of rapidly evolving violaceous patches, infiltrated plaques, and bruise-like tumefactions, disseminated on her face and upper trunk.
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View Article and Find Full Text PDFChin J Cancer Res
December 2024
School of Basic Medical Sciences, Health Science Center, Peking University, Beijing 100191, China.
Exhausted T cell (Tex) is a specific state of T cell dysfunction, in which these T cells gradually lose their effector function and change their phenotype during chronic antigen stimulation. The enrichment of exhausted CD8 T cell (CD8 Tex) in the tumor microenvironment is one of the important reasons leading to the poor efficacy of immunotherapy. Recent studies have reported many reasons leading to the CD8 T cell exhaustion.
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View Article and Find Full Text PDFRSC Adv
January 2025
Department of Chemical Engineering, Polytechnique Montreal Montreal QC Canada
Chitosan, a biodegradable and biocompatible natural polymer composed of β-(1-4)-linked -acetyl glucosamine (GlcNAc) and d-glucosamine (GlcN) and derived from crustacean shells, has been widely studied for various biomedical applications, including drug delivery, cartilage repair, wound healing, and tissue engineering, because of its unique physicochemical properties. One of the most promising areas of research is the investigation of the immunomodulatory properties of chitosan, since the biopolymer has been shown to modulate the maturation, activation, cytokine production, and polarization of dendritic cells and macrophages, two key immune cells involved in the initiation and regulation of innate and adaptive immune responses, leading to enhanced immune responses. Several signaling pathways, including the cGAS-STING, STAT-1, and NLRP3 inflammasomes, are involved in chitosan-induced immunomodulation.
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