MRes in Medical Mycology and Fungal Immunology

MRES项目1利用特定细胞表面靶向抗体研究真菌细胞壁动力学真菌感染是一个值得注意的全球健康问题。它每年造成160万人死亡。免疫受损的人面临更高的风险。然而，目前可用的抗真菌治疗和诊断分析是不够的。这导致迫切需要更好的抗真菌药物和真菌诊断测试。UTR2是一种细胞壁蛋白，在播散性白念珠菌病小鼠模型中参与了白色念珠菌的毒力。因此，噬菌体展示技术已经被用来筛选潜在的高UTR2结合蛋白。在188个克隆中，我们发现1-D2单链抗体片段(Scab)结合效果最好。UTR2多肽与白念珠菌全细胞酶联免疫吸附试验(ELISA法)结合。免疫荧光染色显示菌丝染色阳性。而最小抑菌浓度(MIC)试验未见明显的生长抑制作用。需要进一步的研究来进一步表征1-D2。MREs项目2：PTP1B在调节中性粒细胞真菌杀伤机制中的作用白念珠菌感染在世界范围内造成了重大的死亡率和发病率。先天免疫反应在抗真菌免疫中起着重要作用。尤其是中性粒细胞，是对抗白色念珠菌的有效吞噬细胞。蛋白酪氨酸磷酸酶1B(PTP1B)是一种普遍表达的磷酸酪氨酸特异性磷酸酶，与蛋白酪氨酸激酶协同作用，维持多种细胞信号通路的生理动态平衡。威尔逊博士的实验室观察到，感染白念珠菌的髓系特异性PTP1B基因敲除小鼠的存活率低于野生型对照小鼠。因此，我们评估了PTP1B在调节中性粒细胞中白色念珠菌的杀伤机制中的作用。本研究表明PTP1B抑制对白色念珠菌的中性粒细胞吞噬功能无明显影响。然而，PTP1B抑制减少了血清调理的酵母细胞和菌丝刺激时的峰值活性氧(ROS)的产生，但对未调理的酵母细胞没有影响。此外，抑制PTP1B不影响5小时内总ROS的产生，也不影响中性粒细胞对白色念珠菌的杀灭作用。本研究可能为PTP1B参与烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶介导的ROS产生在白念珠菌感染中的作用提供初步证据。

MRes project 1Investigating fungal cell wall dynamics using specific cell surface targeting antibodiesFungal infection is a notable global health issue. It contributes to 1.6 million deaths annually. Immunocompromised individuals are at increased risk. However, currently available antifungal therapy and diagnostic assays are inadequate. This leads to the urgent need of better antifungal agents and fungal diagnostic tests. UTR2 is a cell wall protein that contributes to Candida albicans virulence in murine model of disseminated candidiasis. Hence, phage display technique has been exploited to screen for potential high UTR2 binder. Here, we found that 1-D2 single chain antibody fragment (scAb) was the best binder among 188 clones. It demonstrated binding in UTR2 peptide and C.albicans whole cell enzyme-linked immunosorbent assay (ELISA). It also showed positive staining of hyphae in immunofluorescence staining. However, there was no growth inhibition effect in minimum inhibitory concentration (MIC) test. Further studies are required to further characterization of 1-D2. MRes project 2 The role of PTP1B in regulating fungal killing mechanisms in neutrophilsCandida albicans (C. albicans) infection contributes to significant mortality and morbidity worldwide. Innate immune response plays an essential role in antifungal immunity. Neutrophils, in particular, are potent phagocytes against C. albicans. Protein tyrosine phosphatase 1B (PTP1B) is a ubiquitously expressed phosphotyrosine-specific phosphatase that co-operates with protein tyrosine kinases to maintain physiological homeostasis of various cellular signalling pathways. Dr Wilson's laboratory has observed that myeloid-specific PTP1B knockout mice infected with C. albicans had decreased survival rate compared to wild-type control mice. Hence, we assessed the role of PTP1B in regulating C. albicans killing mechanisms in neutrophils. This study showed that PTP1B inhibition had no effect on neutrophil phagocytosis of C. albicans. However, PTP1B inhibition reduced peak reactive oxygen species (ROS) production upon stimulation with serum-opsonised yeast cells and hyphae but not with unopsonised yeast cells. Besides, PTP1B inhibition did not affect total ROS production in 5 hours or neutrophil killing of C. albicans. This study might provide a preliminary evidence of PTP1B involvement in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-mediated ROS production upon C. albicans infection.