Concomitant but not causal association between surface charge and inhibition of phagocytosis by cryptococcal polysaccharide.
Concomitant but not causal association between surface charge and inhibition of phagocytosis by cryptococcal polysaccharide.
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表面电荷与隐球菌多糖吞噬作用的抑制之间存在伴随但非因果关系。
DOI：
10.1128/iai.29.2.295-300.1980
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发表时间：
1980
影响因子：
3.1
通讯作者：
Cherniak,R
中科院分区：
文献类型：
--
作者：
Kozel,TR;Reiss,E;Cherniak,R
荚膜多糖抑制吞噬作用的机制尚不清楚。我们研究了新生隐球菌荚膜多糖的负表面电荷和抑制吞噬作用之间的关系。使用含有磷酸根离子的两种聚合物水相体系来评估表面电荷。调理素如正常牛血清和正常人免疫球蛋白G减少了非包囊隐球菌的表面电荷，同时增强了吞噬作用。这些相同的调理素没有影响的吞噬作用或表面电荷的封装隐球菌。正常人免疫球蛋白G的F（ab′）2片段既不增强吞噬作用，也不改变无包囊隐球菌的表面电荷。此外，纯化的隐球菌多糖的非包囊细胞抑制酵母的吞噬作用，并诱导在酵母表面的强负电荷。化学修饰，以减少纯化的隐球菌多糖或完整的封装隐球菌的表面电荷产生的吞噬抑制活性的一个小的损失，但是，所有处理的多糖制剂保留了显着的能力，抑制吞噬的酵母。这些结果表明，表面电荷和抑制吞噬作用之间的关联在很大程度上是间接的，和一个负的表面电荷的存在下不能解释强大的抗吞噬作用的隐球菌多糖。
The mechanism by which capsular polysaccharides inhibit phagocytosis is not clearly understood. We investigated the association between a negative surface charge and inhibition of phagocytosis by the capsular polysaccharide ofCryptococcus neoformans. A two-polymer aqueous-phase system containing phosphate ions was used to assess surface charge. Opsonins such as normal bovine serum and normal human immunoglobulin G reduced the surface charge on non-encapsulated cryptococci and simultaneously enhanced phagocytosis. These same opsonins had no effect on phagocytosis or surface charge of encapsulated cryptococci. F (ab′)2fragments of normal human immunoglobulin G neither enhanced phagocytosis nor altered the surface charge of non-encapsulated cryptococci. Addition of purified cryptococcal polysaccharide to non-encapsulated cells inhibited phagocytosis of the yeast and induced a strong negative charge at the yeast surface. Chemical modification to reduce the surface charge of either purified cryptococcal polysaccharide or intact encapsulated cryptococci produced a small loss of phagocytosis-inhibiting activity; however, all treated polysaccharide preparations retained a significant ability to inhibit phagocytosis of the yeast. These results indicated that the association between surface charge and inhibition of phagocytosis was largely circumstantial, and presence of a negative surface charge could not account for the powerful antiphagocytic action of cryptococcal polysaccharide.