Role of Reactive Oxygen Species in Lymphocyte Development and Function

活性氧在淋巴细胞发育和功能中的作用

• 批准号: 10014150
• 负责人: THOMAS LETO
• 金额: $ 12.49万
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10014150
• 关键词: Adaptive Immune System; Affect; Animal Model; Animals; Antigens; Apoptosis; Area; Arthritis; Autoimmune Process; Autoimmunity; B-Lymphocytes; CD19 gene; Cell Lineage; Cells; Chronic; Chronic Granulomatous Disease; Clinical Protocols; Communicable Diseases; Defect; Development; Disease; Enzymes; Family; Family member; Future; Generations; Goals; Hematopoietic; Homologous Gene; Human; Hydrogen Peroxide; IgG1; Immune; Immune system; Immunity; Immunization; Immunize; Immunoglobulin M; Immunologic Deficiency Syndromes; In Vitro; Infection; Inflammatory; Inflammatory Bowel Diseases; Interleukin-4; Investigation; Isoenzymes; Knockout Mice; Link; Lipopolysaccharides; Lupus; Lymphocyte; Lymphoid; Lymphoid Cell; Mediating; Modeling; Molecular; Mus; NADP; NADPH Oxidase; Nox enzyme; Oxidants; Oxidases; Oxidation-Reduction; Oxidative Stress; Oxygen; Pathogenesis; Pathologic Processes; Patients; Phagocytes; Phase; Plasma Cells; Play; Population; Process; Production; Proliferating; Protein Isoforms; Reactive Oxygen Species; Receptor Signaling; Receptors, Antigen, B-Cell; Regulation; Research; Role; Serum; Signal Transduction; Signaling Molecule; Stimulus; Structure of germinal center of lymph node; Superoxides; T-Cell Receptor; T-Lymphocyte; Work; adaptive immune response; base; catalase; early onset; genetic manipulation; microbial; mouse model; pathogen; programs; response; translational study

This program explores roles of reactive oxygen species (ROS) as specific signaling molecules in B and T lymphocytes through genetic manipulation of NOX/DUOX family NADPH oxidases. These enzymes catalyze NADPH-dependent reduction of molecular oxygen to generate superoxide or hydrogen peroxide. Phagocytes produce large amounts of ROS in response to infectious or inflammatory stimuli through the prototypic NADPH oxidase containing gp91phox (a.k.a., CYBB or NOX2). Although originally understood as an oxidant-dependent microbial killing mechanism deployed by phagocytes, our research revealed that ROS intentionally generated by other NOX homologues play specific signaling roles in B cell receptor (BCR)-stimulated B cells and T cell receptor (TCR)-stimulated T cells. Our studies in lymphocytes are exploring roles of NOX family members in adaptive immune responses to diverse pathogens, as well as in immunodeficiencies and autoimmunity. Several NOX family oxidases have been associated with auto-immune inflammatory disease-like processes, such as arthritis, lupus and inflammatory bowel disease. About 40-50% of chronic granulomatous disease patients with NOX2 deficiencies suffer from autoimmune complications and very early onset inflammatory bowel disease (VEOIBD). Deficiencies in several other NOX isozymes have been linked to inflammatory bowel disease, although it is remains clear whether these oxidase defects are manifested in lymphoid or other hematopoietic cell lineages. In 2019, we completed studies on the involvement of Duox1 in B lymphocyte responses to IL-4 and B cell receptor stimulation. We showed that Duox1 is induced in murine B lymphocytes treated with IL-4 in vitro and that co-stimulation through B cell receptors (BCR) generates a ROS signal attributable to Duox1. Interestingly, stimulated Duox1-deficient B cells proliferate in vitro more rapidly than wild type or NOX2-deficient B cells, which was correlated with enhanced expression of several BCR signaling intermediates (Akt, BCAP and RGS16). Furthermore, we demonstrated that the hydrogen peroxide scavenger catalase mimics the effect of Duox1 deficiency by enhancing proliferation of wild type CD19+ B cells in vitro. In contrast, NOX2-deficient B cells showed enhanced apoptosis and diminished IgM, IgG1 and IgG2a production relative to wild type or DUOX1-/- cells. These observations were correlated with whole animal immunization findings: the Duox1 knockout mice immunized with T cell-dependent (TD) or -independent (TI) antigens produce normal serum Ig levels, but immunization with the TI antigen, nitrophenyl-lipopolysaccharide (NP-LPS), resulted in more numerous and enlarged splenic reactive (Ki67 and peanut antigen positive) germinal centers in Duox1 knockout mice when compared with wild type or NOX2-deficient mice. Our results suggest Duox1 may have a role in limiting early proliferative responses to BCR stimulation, particularly with pathogens that avoid T cell recognition. Thus, the ROS generated by distinct NOX isozymes have different effects on the fate and function of stimulated lymphoid cell populations. Future work should explore roles for Duox1 in generation of long-lived plasma cells or in infection models where Th2-based immunity prevails.

本项目通过对NOX/DUOX家族NADPH氧化酶的基因操纵，探索活性氧（ROS）在B淋巴细胞和T淋巴细胞中作为特定信号分子的作用。这些酶催化nadph依赖的分子氧还原生成超氧化物或过氧化氢。吞噬细胞通过含有gp91phox（又名CYBB或NOX2）的原型NADPH氧化酶对感染或炎症刺激产生大量ROS。虽然最初被认为是一种由吞噬细胞部署的氧化剂依赖的微生物杀死机制，但我们的研究表明，其他NOX同系物有意产生的ROS在B细胞受体（BCR）刺激的B细胞和T细胞受体（TCR）刺激的T细胞中发挥特定的信号作用。我们在淋巴细胞中的研究正在探索NOX家族成员在对多种病原体的适应性免疫反应以及免疫缺陷和自身免疫中的作用。几种氮氧化物家族氧化酶与自身免疫性炎症样疾病有关，如关节炎、狼疮和炎症性肠病。约40-50%的慢性肉芽肿性疾病NOX2缺乏患者患有自身免疫性并发症和极早发性炎症性肠病（VEOIBD）。其他几种氮氧化物同工酶的缺乏与炎症性肠病有关，尽管尚不清楚这些氧化酶缺陷是否表现在淋巴细胞或其他造血细胞谱系中。