SIC, a secreted protein of Streptococcus pyogenes that inactivates antibacterial peptides
SIC, a secreted protein of Streptococcus pyogenes that inactivates antibacterial peptides
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DOI：
10.1074/jbc.m301995200
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发表时间：
2003-05-09
影响因子：
4.8
通讯作者：
Björck, L
中科院分区：
文献类型：
--
作者：
Frick, IM;Åkesson, P;Björck, L
一些重要的人类病原体化脓性链球菌的分离株，包括M1血清型的强毒株，会分泌SIC蛋白。这种分子大量分泌，干扰补体功能。作为自然选择的结果，碳化硅表现出高度的变异。在这里，我们为这种变异和M1血清型菌株是严重侵袭性化脓性链球菌感染的最常见原因提供了一个可信的解释。因此，蛋白质SIC被发现可以灭活人中性粒细胞α-防御素和LL-37，这两种主要抗菌肽参与了细菌清除。这种灭活保护化脓性链球菌不受多肽的抗菌作用。此外，从M1血清型化脓性链球菌分离出的SIC在这方面比从M血清型12和55菌株分离的SIC变异体更有效，而M血清型很少与侵袭性感染有关。
Some isolates of the significant human pathogen Streptococcus pyogenes, including virulent strains of the M1 serotype, secrete protein SIC. This molecule, secreted in large quantities, interferes with complement function. As a result of natural selection, SIC shows a high degree of variation. Here we provide a plausible explanation for this variation and the fact that strains of the M1 serotype are the most frequent cause of severe invasive S. pyogenes infections. Thus, protein SIC was found to inactivate human neutrophil alpha-defensin and LL-37, two major antibacterial peptides involved in bacterial clearance. This inactivation protected S. pyogenes against the antibacterial effect of the peptides. Moreover, SIC isolated from S. pyogenes of the M1 serotype was more powerful in this respect than SIC variants from strains of M serotypes 12 and 55, serotypes rarely connected with invasive infections.