Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Marine Biopharmaceutical Institute, Second Military Medical University, 800 Xiangyin Road, Shanghai, 200433, China; School of Pharmacy, Second Military Medical University, 325 Guohe Road, Shanghai, 200433, China.
Department of Dermatology, Changzheng Hospital, Second Military Medical University, 415 Fengyang Road, Shanghai, 200003, China.
Eur J Med Chem. 2019 Jul 1;173:250-260. doi: 10.1016/j.ejmech.2019.04.001. Epub 2019 Apr 5.
Fungal cell surface carbohydrates and proteins are useful antigens for the development of antifungal vaccines. In this study, glycopeptides consisting of the β-1,2-mannan and N-terminal peptide epitopes of Candida albicans (C. albicans) cell wall phosphomannan complex and Als1p (rAls1p-N) protein, respectively, were synthesized and covalently conjugated with keyhole limpet hemocyanin (KLH) and human serum albumin (HSA) through homobifunctional disuccinimidyl glutarate. The resultant KLH-conjugates were immunologically evaluated using Balb/c mice to reveal that they induced high levels of IgG antibodies. Furthermore, these conjugates showed self-adjuvanting property, as they could promote robust antibody responses without the presence of an external adjuvant. More significantly, the obtained antisera could effectively recognize both the carbohydrate and the Als1 peptide epitopes and immunofluorescence and flow cytometry assays also demonstrated that the elicited antibodies could react with the cell surface of a number of fungi, including C. albicans, C. tropicalis, C. lustaniae and C. glabrata. These results suggested the great potential of these conjugates as antifungal vaccines.
真菌细胞表面的碳水化合物和蛋白质是开发抗真菌疫苗的有用抗原。在这项研究中，分别合成了含有白色念珠菌（C. albicans）细胞壁磷酸甘露聚糖复合物β-1,2-甘露聚糖和 N 端肽表位的糖肽（C. albicans）和 Als1p（rAls1p-N）蛋白，并通过同双功能琥珀酰亚胺戊二酸将其共价连接到钥孔血蓝蛋白（KLH）和人血清白蛋白（HSA）上。使用 Balb/c 小鼠对所得 KLH 缀合物进行了免疫评估，结果表明它们诱导了高水平的 IgG 抗体。此外，这些缀合物具有自身佐剂特性，因为它们可以在没有外部佐剂的情况下促进强烈的抗体反应。更重要的是，获得的抗血清可以有效地识别碳水化合物和 Als1 肽表位，免疫荧光和流式细胞术分析也表明，所产生的抗体可以与包括白色念珠菌、热带念珠菌、光滑念珠菌和近平滑念珠菌在内的多种真菌的细胞表面发生反应。这些结果表明这些缀合物作为抗真菌疫苗具有巨大的潜力。
