Burjack Juliana R, Santana-Filho Arquimedes P, Ruthes Andrea C, Riter Daniel S, Vicente Vania A, Alvarenga Larissa M, Sassaki Guilherme L
Química de Carboidratos, Departamento de Patologia Básica, Universidade Federal do Paraná Curitiba, Brazil.
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná Curitiba, Brazil.
Front Cell Infect Microbiol. 2014 Oct 31;4:153. doi: 10.3389/fcimb.2014.00153. eCollection 2014.
Dematiaceous fungi constitute a large and heterogeneous group, characterized by having a dark pigment, the dihydroxynaftalen melanin-DHN, inside their cell walls. In nature they are found mainly as soil microbiota or decomposing organic matter, and are spread in tropical and subtropical regions. The fungus Fonsecaea monophora causes chromoblastomycosis in humans, and possesses essential mechanisms that may enhance pathogenicity, proliferation and dissemination inside the host. Glycoconjugates confer important properties to these pathogenic microorganisms. In this work, structural characterization of glycan structures present in two different strains of F. monophora MMHC82 and FE5p4, from clinical and environmental origins, respectively, was performed. Each one were grown on Minimal Medium (MM) and Czapeck-Dox (CD) medium, and the water soluble cell wall glycoconjugates and exopolysaccharides (EPS) were evaluated by NMR, methylation and principal component analysis (PCA). By combining the methylation and 2D NMR analyses, it was possible to visualize the glycosidic profiles of the complex carbohydrate mixtures. Significant differences were observed in β-D-Galf-(1→5) and (1→6) linkages, α- and β-D-Glcp-(1→3), (1→4), and (1→6) units, as well as in α-D-Manp. PCA from (1)H-NMR data showed that MMHC82 from CD medium showed a higher variation in the cell wall carbohydrates, mainly related to O-2 substituted β-D-Galf (δ 106.0/5.23 and δ 105.3/5.23) units. In order to investigate the antigenic response of the glycoconjugates, these were screened against serum from chromoblastomycosis patients. The antigen which contained the cell wall of MMHC82 grown in MM had β-D-Manp units that promoted higher antigenic response. The distribution of these fungal species in nature and the knowledge of how cell wall polysaccharides and glycoconjugates structure vary, may contribute to the better understanding and the elucidation of the pathology caused by this fungus.
暗色丝孢真菌是一个庞大且异质的类群，其特征是在细胞壁内含有一种深色色素——二羟基萘黑色素-DHN。在自然界中，它们主要作为土壤微生物群或分解的有机物存在，并分布于热带和亚热带地区。单孢瓶霉真菌可导致人类患着色芽生菌病，且拥有可能增强其在宿主体内致病性、增殖和传播的关键机制。糖缀合物赋予这些致病微生物重要特性。在这项研究中，对分别来自临床和环境来源的单孢瓶霉MMHC82和FE5p4两个不同菌株中存在的聚糖结构进行了结构表征。将每个菌株分别在基本培养基（MM）和察氏培养基（CD）上培养，并通过核磁共振（NMR）、甲基化和主成分分析（PCA）对水溶性细胞壁糖缀合物和胞外多糖（EPS）进行评估。通过结合甲基化分析和二维NMR分析，得以观察到复杂碳水化合物混合物的糖苷谱。在β-D-半乳糖-(1→5)和(1→6)连接、α-和β-D-葡萄糖-(1→3)、(1→4)和(1→6)单元以及α-D-甘露糖方面观察到显著差异。基于氢核磁共振（¹H-NMR）数据的主成分分析表明，在CD培养基上培养的MMHC82在细胞壁碳水化合物方面表现出更高的变异性，主要与O-2取代的β-D-半乳糖（δ 106.0/5.23和δ 105.3/5.23）单元有关。为了研究糖缀合物的抗原反应，用其针对着色芽生菌病患者的血清进行筛选。含有在MM培养基上生长的MMHC82细胞壁的抗原具有β-D-甘露糖单元，能引发更高的抗原反应。这些真菌物种在自然界中的分布以及对细胞壁多糖和糖缀合物结构如何变化的了解，可能有助于更好地理解和阐明由这种真菌引起的病理学。
