Objective: To study the effect of miR-138 on the function of osteosarcoma (OS) T follicular helper cells (Tfh cells) and its mechanism.
Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from patients with osteosarcoma (OS group) and healthy volunteers (control group). CD4+CXCR5+ Tfh cells and CD9+ B cells were sorted by flow cytometry. qRT-PCR was used to detect the expression of miR-138 and PDK1 in the peripheral blood and CD4+CXCR5+ Tfh cells. Flow cytometry was employed to detect the proportion of CD4+CXCR5+ Tfh cells in CD4+ T cells, the level of CD40L in CD4+CXCR5+ Tfh cells, and the expression of CD27 and CD38 in B cells. Western blot was used to determine the protein expression of PDK1, PI3K, p-Akt, Akt, p-mTOR, and mTOR. In addition, dual-luciferase reporter assay was performed to verify the relationship between miR-138 and PDK1. ELISA method was used to determine the levels of IgM, IgG, IL-10, and IL-21.
Results: Compared with that of the control group, the expression of miR-138 in PBMC and CD4+CXCR5+ Tfh cells of the OS group was lower; overexpression of miR-138 could promote the maturation of Tfh cells and immature B cells. The results of the dual-luciferase report experiment showed that miR-138 can target and negatively regulate PDK1, and PDK1 can reverse the effect of miR-138 on the function of Tfh cells and immature B cells.
Conclusion: miR-138 inhibits the PI3K/Akt/mTOR pathway by targeting and negatively regulating PDK1 to alleviate the dysfunction of T follicular helper cells in OS.
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http://dx.doi.org/10.1155/2021/2895893 | DOI Listing |
Rheumatology (Oxford)
January 2025
Department of Rheumatology and Immunology and Beijing Key Laboratory for Rheumatism and Immune Diagnosis (BZ0135), Peking University People's Hospital, Beijing, 100044, China.
Objectives: The objective of this study was to evaluate the efficacy and safety of tofacitinib in the treatment of active dermatomyositis (DM) and anti-synthetase syndrome (ASS).
Methods: Tofacitinib was administered at a dose of 5 mg twice daily to patients who exhibited inadequate response to conventional treatments. The primary end point was the reduction of T follicular helper (Tfh) cells at week 24.
EMBO Mol Med
January 2025
Medical Clinic III for Oncology, Hematology, Immuno-Oncology and Rheumatology, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.
Studying the human immune system in vivo is challenging and often not possible. Therefore, most human immunology studies have been predominantly confined to peripheral blood analyses, which by themselves have inherent limitations, as many immune reactions take place within tissues. For example, potent antibody responses that contribute to fighting infections and provide protection following vaccination require cellular interactions between B cells and T cells in specialized micro-anatomical structures called germinal centers, which are found in secondary lymphoid organs such as spleen, lymph nodes, and tonsils.
View Article and Find Full Text PDFUnlabelled: Dendritic cells (DCs) are key regulators of adaptive immunity, guiding T helper (Th) cell differentiation through antigen presentation, co-stimulation, and cytokine production. However, in steady-state conditions, certain DC subsets, such as Langerhans cells (LCs), induce T follicular helper (Tfh) cells and B cell responses without inflammatory stimuli. Using multiple mouse models and systems, we investigated the mechanisms underlying steady-state LC-induced adaptive immune responses.
View Article and Find Full Text PDFbioRxiv
January 2025
Department of Chemistry, 409 McCormick Road, University of Virginia, Charlottesville, VA 22904.
Antibody production is central to protection against new pathogens and cancers, as well as to certain forms of autoimmunity. Antibodies often originate in the lymph node (LN), specifically at the extrafollicular border of B cell follicles, where T and B lymphocytes physically interact to drive B cell maturation into antibody-secreting plasmablasts. In vitro models of this process are sorely needed to predict aspects of the human immune response.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), Majadahonda, 28220 Madrid, Spain.
Class IA PI3K p110δ and p110α subunits participate in TCR and costimulatory receptor signals involved in T cell-mediated immunity, but the role of p110α is not completely understood. Here, we analyzed a mouse model of the Cre-dependent functional inactivation of p110α (kinase dead) in T lymphocytes (p110αKD-T, KD). KD mice showed increased cellularity in thymus and spleen and altered T cell differentiation with increased number of CD4CD8 DP thymocytes, enhanced proportion of CD4 SP lymphocytes linked to altered apoptosis, lower Treg cells, and increased AKT and ERK phosphorylation in activated thymocytes.
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