The Elastic Properties of the Cryptococcus neoformans Capsule
The Elastic Properties of the Cryptococcus neoformans Capsule
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DOI：
10.1016/j.bpj.2009.04.043
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发表时间：
2009-08-19
影响因子：
3.4
通讯作者：
Casadevall, Arturo
中科院分区：
文献类型：
--
作者：
Frases, Susana;Pontes, Bruno;Casadevall, Arturo
微生物荚膜对毒力很重要，但其结构和物理性质知之甚少。人类致病性真菌新型隐球菌具有大的多糖荚膜，其是毒力所必需的，并且是保护性抗体应答的目标。为了研究C.我们开发了我们认为是新的方法，由此我们通过使用用光学镊子操纵的聚苯乙烯珠施加力来探测囊的弹性性质。这种方法使我们能够确定在影响胶囊生长的各种条件下胶囊的杨氏模量。结果表明，胶囊的杨氏模量随胶囊尺寸的增大而减小，随溶液中Ca ~（2+）浓度的增大而增大。此外，荚膜多糖表现出对聚苯乙烯珠的意想不到的亲和力，这是一种可能在附着于宿主细胞和环境结构中起作用的性质。微珠探测与光镊提供了一种新的，非破坏性的方法，可能具有广泛的适用性，用于研究生长条件，免疫成分和药物对胶囊性能的影响。
Microbial capsules are important for virulence, but their architecture and physical properties are poorly understood. The human pathogenic fungus Cryptococcus neoformans has a large polysaccharide capsule that is necessary for virulence and is the target of protective antibody responses. To study the C. neoformans capsule we developed what we believe is a new approach whereby we probed the capsular elastic properties by applying forces using polystyrene beads manipulated with optical tweezers. This method allowed us to determine the Young's modulus for the capsule in various conditions that affect capsule growth. The results indicate that the Young's modulus of the capsule decreases with its size and increases with the Ca2+ concentration in solution. Also, capsular polysaccharide manifests an unexpected affinity for polystyrene beads, a property that may function in attachment to host cells and environmental structures. Bead probing with optical tweezers provides a new, nondestructive method that may have wide applicability for studying the effects of growth conditions, immune components, and drugs on capsular properties.