INFLUENCE OF SEROTYPE OF GROUP-B STREPTOCOCCI ON C3 DEGRADATION
INFLUENCE OF SEROTYPE OF GROUP-B STREPTOCOCCI ON C3 DEGRADATION
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DOI：
10.1128/iai.60.11.4558-4562.1992
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发表时间：
1992-11-01
影响因子：
3.1
通讯作者：
EDWARDS, MS
中科院分区：
文献类型：
--
作者：
CAMPBELL, JR;BAKER, CJ;EDWARDS, MS
B 组链球菌 (GBS) 血清型 III 菌株是从大多数患有菌血症或脑膜炎的小婴儿中分离出来的。我们假设，类型特异性荚膜多糖结构中与血清型相关的差异或 c 蛋白的存在会影响 GBS 上 C3 降解的程度，并且类型特异性抗体会改变 C3 沉积或降解模式。当代表血清型 Ia、Ib/c、II（有或没有 c 蛋白）和 III 的 GBS 临床分离株与低丙种球蛋白血清作为调理源一起使用时，四种 GBS 血清型以及有或没有 c 蛋白的菌株之间的 C3 沉积和降解模式观察到显着的相似性。 C3b 和 iC3b 在 5 分钟内和整个 90 分钟调理间隔内均被检测到。 5 分钟后，Ia 和 Ib/c 血清型的沉积量少于 II 型和 III 型 GBS。观察到最小程度的降解为 C3d 或更小的片段。类型特异性抗体促进 C3b 在 GBS 上沉积，并在调理作用早期促进 C3b 降解为 iC3b。可能是 C3 片段与中性粒细胞受体的可及性，而不是表面允许 C3 降解的程度，解释了 GBS 血清型之间的毒力差异。
Serotype III strains of group B streptococci (GBS) are isolated from the majority of young infants with bacteremia or meningitis. We hypothesized that serotype-associated differences in structure of the type-specific capsular polysaccharide or the presence of c protein would influence the extent to which C3 degradation occurs on GBS and that type-specific antibody would alter C3 deposition or degradation patterns. When clinical isolates of GBS representing serotypes Ia, Ib/c, II (with or without c protein), and III were employed with hypogammaglobulinemic serum as an opsonic source, a remarkable similarity was observed in patterns of C3 deposition and degradation for each of the four GBS serotypes and between strains with or without c protein. Both C3b and iC3b were detected by 5 min and throughout a 90-min opsonization interval. Less deposition occurred at 5 min on serotypes Ia and Ib/c than on types II and III GBS. Minimal degradation to C3d or smaller fragments was observed. Type-specific antibody facilitated C3b deposition on GBS and C3b degradation to iC3b early in opsonization. Possibly, accessibility of C3 fragments to neutrophil receptors, rather than the extent to which the surface permits C3 degradation, accounts for differential virulence among GBS serotypes.