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Invariant natural killer T (iNKT) cells recognize activating self and microbial lipids presented by CD1d. CD1d can also bind non-activating lipids, such as sphingomyelin. We hypothesized that these serve as endogenous regulators and investigated humans and mice deficient in acid sphingomyelinase (ASM), an enzyme that degrades sphingomyelin. We show that ASM absence in mice leads to diminished CD1d-restricted antigen presentation and iNKT cell selection in the thymus, resulting in decreased iNKT cell levels and resistance to iNKT cell-mediated inflammatory conditions. Defective antigen presentation and decreased iNKT cells are also observed in ASM-deficient humans with Niemann-Pick disease, and ASM activity in healthy humans correlates with iNKT cell phenotype. Pharmacological ASM administration facilitates antigen presentation and restores the levels of iNKT cells in ASM-deficient mice. Together, these results demonstrate that control of non-agonistic CD1d-associated lipids is critical for iNKT cell development and function in vivo and represents a tight link between cellular sphingolipid metabolism and immunity.
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http://dx.doi.org/10.1038/s41590-019-0504-0 | DOI Listing |
EMBO J
September 2025
Department of Infectious Diseases, Medical Research Institute, Zhongnan Hospital of Wuhan University; Frontier Science Center for Immunology and Metabolism, Taikang Center for Life and Medical Sciences; Wuhan University, Wuhan, 430071, China.
Inadequate antigen presentation by MHC-I in tumor microenvironment (TME) is a common immune escape mechanism. Here, we show that glycine decarboxylase (GLDC), a key enzyme in glycine metabolism, functions as an inhibitor of MHC-I expression in EGFR-activated tumor cells to induce immune escape by a mechanism independent of its enzymatic activity. Upon EGFR activation, GLDC is phosphorylated by SRC and subsequently translocated to the nucleus in human NSCLC cells.
View Article and Find Full Text PDFBiotechnol Lett
September 2025
Department of Chemical Engineering, Hongik University, Sangsu-dong, Mapo-gu, Seoul, 04066, Republic of Korea.
The cell surface display system employs carrier proteins to present target proteins on the outer membrane of cells. This system enables functional proteins to be exposed on the exterior of living cells without cell lysis, allowing direct interaction with the surrounding environment. A major limitation of conventional approaches is the difficulty in displaying large-sized enzymes or antibodies, despite their critical roles in applications requiring functional domains that must remain intact, such as catalytic or antigen-binding sites.
View Article and Find Full Text PDFJ Inflamm Res
September 2025
Department of the Head and Neck, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Peking University Cancer Hospital Yunnan, Kunming, People's Republic of China.
Background: Immune escape of tumor cells is a common problem with tumor photothermal therapy utilizing gold nanorods (Au NRs). Whether CpG ODN, an immune adjuvant, can synergize with Au NRs to activate the immune response and its potential mechanism is not clear.
Methods: The effect of Au NRs combined with CpG ODN (Au NRs-C) on the activity of various immune-related cells, such as double-positive T cells, macrophages, NK cells, Th17, and Treg.
J Control Release
September 2025
School of Pharmaceutical Sciences, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China. Electronic address:
Fusobacterium nucleatum (Fn.) can colonize breast cancer tissue to promote tumor progression by inducing immunosuppression. Targeted therapeutic strategies against intratumoral bacteria remain unexplored and have potential in tumor immunotherapy.
View Article and Find Full Text PDFCrit Rev Immunol
September 2025
Department of Biochemistry, University of Kerala, Kariavattom, Thiruvananthapuram, Kerala, India 695581.
Rheumatoid arthritis (RA) is a chronic autoimmune condition that impacts the immune system, especially through changes in the splenic immune cell system. This review provides an overview of the role of splenocytes in T cell signaling and their immune response in RA patients. The spleen acts as a critical site for the activation and differentiation of splenic immune cells like T cells, B cells, macrophages, dendritic cells, and NK cells.
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