Role of host sphingolipids against fungal infections

宿主鞘脂对抗真菌感染的作用

• 批准号: 10554304
• 负责人: Maurizio Del Poeta
• 金额: --
• 依托单位: NORTHPORT VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-10-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10554304
• 关键词: Alveolar Macrophages; Animals; Antibodies; Brain; Cell membrane; Cell physiology; Cells; Cellular Immunity; Ceramides; Cholesterol; Communicable Diseases; Cryptococcosis; Cryptococcus neoformans; Cryptococcus neoformans infection; Cyclic AMP-Dependent Protein Kinases; Defensins; Development; Diffusion; Diglycerides; Disease; Disease Outcome; Environment; Exposure to; Flow Cytometry; Functional disorder; Genes; Goals; Granuloma; Host resistance; Human; Immune; Immune response; Immunity; Immunocompetent; Immunologic Deficiency Syndromes; Immunotherapy; In Vitro; Individual; Infection; Infection Control; Inflammatory Response; Inhalation; Laboratories; Lecithin; Life; Lipids; Lung; Macrophage; Mediating; Membrane; Membrane Microdomains; Military Personnel; Mus; Mycoses; Nitric Oxide; Pathway interactions; Peptides; Phagocytes; Phagocytosis; Phosphorylcholine; Play; Predisposition; Production; Progress Reports; Reactive Oxygen Species; Regulation; Role; Signal Pathway; Site; Sphingolipids; Sphingomyelins; Testing; antimicrobial; antimicrobial peptide; extracellular; insight; novel therapeutic intervention; pathogenic fungus; protein kinase D; pulmonary granuloma; receptor; sphingomyelin synthase

ABSTRACT The goal of this project is to study the role and mechanisms by which sphingomyelin synthases (Sms1 and Sms2) are involved in controlling the infection caused by the pathogenic fungus Cryptococcus neoformans (Cn). Our laboratory has pioneered studies dealing with the role of fungal sphingolipids in the regulation of infectious diseases. In addition to studying fungal sphingolipids, we have recently discovered that certain host sphingolipids play a key role in controlling the immune response against the human fungal pathogen Cn. One of the host sphingolipid shown to regulate immune responses is sphingomyelin (SM) produced by sphingomyelin synthase (SMS), encoded by the SMS1 and SMS2 genes.1,2 SMS transfers a choline phosphate moiety from phosphatidylcholine (PC) to ceramide, producing SM and diacylglycerol (DAG) (Fig. 1).3,4 These lipids have been implicated in many cellular functions including the activation of pro-inflammatory responses,5 suggesting that the regulation of SMS activity in immune cells may assume a critical role in controlling infections. In fact, we have shown previously that the DAG produced by SMS mediates the in vitro extracellular killing of Cn by phagocytic cells possibly through a protein kinase D (PKD) dependent mechanism, and the SMS-DAG-PKD signaling pathway mediates the secretion of antimicrobial peptides by phagocytic cells, particularly defensins (§ Progress Report, new Fig. 9, and6,7). Very intriguingly, our current studies also revealed a key role for SM in the regulation of cholesterol-rich membrane rafts in macrophages. We found that depletion of SM in the outer membrane of macrophages dramatically decreases phagocytosis (Figs. 3 and 5) and displaces the Fcg receptor (FcgR) from a punctuated, clustered to a diffused and homogeneous distribution (Fig. 7). This phenomenon was validated when cholesterol was depleted (Fig. 7), corroborating the association of the FcgR with lipid rafts. The resulting effect of these depletions is a significant decrease of antibody-mediated phagocytosis of Cn (Figs. 3, 4 and 5). Importantly, the displacement of the FcgR was also observed in alveolar macrophages isolated from mice lacking Sms1 (sms1-/-) or Sms2 (sms2-/-), which also showed a decrease of antibody-mediated phagocytosis (new Fig. 12). Taken together, these results suggest that SMS regulates the internalization of Cn cells by macrophages through the production of SM, which, at the plasma membrane, stabilizes cholesterol-rich lipid rafts (new Fig. 8) for anchoring the FcgR. Deletion of Sms1 (sms1-/-) or Sms2 (sms2-/-) renders the animals significantly hypersusceptible to Cn infection (Fig. 10). Upon inhalation, Cn cells are rapidly replicating in the lung and quickly disseminating to the brain of sms1-/- or sms2-/- mice (new Fig. 11). Preliminary flow cytometry shows a different immuno cellular composition in sms2-/- compared to WT lungs (new Fig. 15), and the sms2-/- mice cannot form an efficient lung granuloma (new Fig. 13). These results suggest that the regulation of SMS at the Cn-macrophage interface in the lung environment may have a key role in the regulation of the overall host immunity and the outcome of the disease. Based on these studies, we hypothesize that, through the production of SM and DAG, SMS regulates the phagocytosis/killing of Cn, stimulating an effective host immune response against Cn. Thus, we propose the following aims: 1) To determine the mechanism by which SMS regulates phagocytosis and killing of Cn by phagocytic cells; and 2) To establish the role and mechanism(s) by which SMS regulates the overall host immunity against Cn. By studying the role of SMS during Cn-phagocytes interaction and during the infection we will be able to identify new mechanisms of host protection with important insights into the development of new immunotherapies to better control this life-threatening disease.

摘要 本项目的目的是研究鞘磷脂酶（Sms 1和Sms 2）在细胞内的作用和机制。 参与控制由致病真菌新型隐球菌（Cn）引起的感染。 我们的实验室率先研究了真菌鞘脂在调节感染性疾病中的作用。 疾病除了研究真菌鞘脂，我们最近发现，某些宿主鞘脂发挥作用， 在控制针对人类真菌病原体Cn的免疫应答中起关键作用。宿主鞘脂之一 显示调节免疫应答的是由鞘磷脂合酶（SMS）产生的鞘磷脂（SM）， SMS 1和SMS 2基因1，2 SMS将磷酸胆碱部分从磷脂酰胆碱（PC）转移到神经酰胺， 产生SM和二酰基甘油（DAG）（图1）。3，4这些脂质与许多细胞功能有关，包括 促炎反应的激活，5表明免疫细胞中SMS活性的调节可能 在控制感染方面发挥关键作用。事实上，我们之前已经证明，由SMS产生的DAG 介导吞噬细胞对Cn的体外细胞外杀伤，可能是通过蛋白激酶D（PKD）依赖性 SMS-DAG-PKD信号通路介导吞噬细胞分泌抗菌肽 细胞，特别是防御素（§进展报告，新图9和6，7）。 非常有趣的是，我们目前的研究还揭示了SM在调节富含胆固醇的膜中的关键作用。 巨噬细胞中的筏。我们发现，在巨噬细胞外膜的SM消耗显着减少， 吞噬作用（图3和5）并将Fcg受体（FcgR）从点状、成簇的置换成弥散的和 均匀分布（图7）。当胆固醇耗尽时，这种现象得到验证（图7）， 证实了FcgR与脂筏的结合。这些消耗的结果是， 抗体介导的Cn吞噬作用（图3、4和5）。 重要的是，在从缺乏FcgR的小鼠分离的肺泡巨噬细胞中也观察到FcgR的置换。 Sms 1（sms 1-/-）或Sms 2（sms 2-/-），其也显示抗体介导的吞噬作用降低（新图12）。 综上所述，这些结果表明，SMS通过巨噬细胞调节Cn细胞的内化， SM的产生，其在质膜上稳定富含胆固醇的脂筏（新的图8），用于锚定 FcgR。 Sms 1（sms 1-/-）或Sms 2（sms 2-/-）的缺失使动物对Cn感染显著易感 (Fig. 10）。吸入后，Cn细胞在肺中迅速复制，并迅速扩散到sms 1-/-的脑中。 或sms 2-/-小鼠（新的图11）。初步的流式细胞术显示sms 2-/-中不同的免疫细胞组成。 与WT肺相比，sms 2-/-小鼠不能形成有效的肺肉芽肿（新的图15）。 这些结果表明，在肺环境中，SMS对Cn-巨噬细胞界面的调节可能具有一定的作用。 在调节整体宿主免疫力和疾病结果中起关键作用。 基于这些研究，我们推测，通过SM和DAG的产生，SMS调节了细胞的增殖， 在某些实施方案中，本发明的方法可以通过抑制Cn的吞噬/杀死，刺激针对Cn的有效宿主免疫应答。因此，我们提出以下建议 目的： 1)为了确定SMS调节吞噬作用和吞噬细胞对Cn的杀伤作用的机制， 2）确定SMS调节宿主整体免疫力的作用和机制， CN. 通过研究SMS在Cn-吞噬细胞相互作用期间和感染期间的作用，我们将能够鉴定 宿主保护的新机制，对新免疫疗法的发展有重要的见解， 控制这种威胁生命的疾病。

项目成果

The Heat Shock Transcription Factor HsfA Is Essential for Thermotolerance and Regulates Cell Wall Integrity in Aspergillus fumigatus.

热休克转录因子HSFA对于耐热性至关重要，并调节曲霉中的细胞壁完整性。

• DOI: 10.3389/fmicb.2021.656548
• 发表时间: 2021
• 期刊: Frontiers in microbiology
• 影响因子: 5.2
• 作者: Fabri JHTM;Rocha MC;Fernandes CM;Persinoti GF;Ries LNA;da Cunha AF;Goldman GH;Del Poeta M;Malavazi I
• 通讯作者: Malavazi I

Cryptococcal Meningitis Reported With Fingolimod Treatment: Case Series.

• DOI: 10.1212/nxi.0000000000001156
• 发表时间: 2022-05
• 期刊: Neurology(R) neuroimmunology & neuroinflammation
• 作者: Del Poeta M;Ward BJ;Greenberg B;Hemmer B;Cree BAC;Komatireddy S;Mishra J;Sullivan R;Kilaru A;Moore A;Hach T;Berger JR
• 通讯作者: Berger JR

Role of Sterylglucosidase 1 (Sgl1) on the pathogenicity of Cryptococcus neoformans: potential applications for vaccine development.

• DOI: 10.3389/fmicb.2015.00836
• 发表时间: 2015
• 期刊: Frontiers in microbiology
• 影响因子: 5.2
• 作者: Rella A;Mor V;Farnoud AM;Singh A;Shamseddine AA;Ivanova E;Carpino N;Montagna MT;Luberto C;Del Poeta M
• 通讯作者: Del Poeta M

Screening of Chemical Libraries for New Antifungal Drugs against Aspergillus fumigatus Reveals Sphingolipids Are Involved in the Mechanism of Action of Miltefosine.

• DOI: 10.1128/mbio.01458-21
• 发表时间: 2021-08-31
• 期刊: mBio
• 影响因子: 6.4
• 作者: Dos Reis TF;Horta MAC;Colabardini AC;Fernandes CM;Silva LP;Bastos RW;Fonseca MVL;Wang F;Martins C;Rodrigues ML;Silva Pereira C;Del Poeta M;Wong KH;Goldman GH
• 通讯作者: Goldman GH

Sphingolipids and Inositol Phosphates Regulate the Tau Protein Phosphorylation Status in Humanized Yeast.

• DOI: 10.3389/fcell.2020.592159
• 发表时间: 2020
• 期刊: Frontiers in cell and developmental biology
• 影响因子: 5.5
• 作者: Randez-Gil F;Bojunga L;Estruch F;Winderickx J;Del Poeta M;Prieto JA
• 通讯作者: Prieto JA