Niche and Neutral Effects of Acquired Immunity Permit Coexistence of Pneumococcal Serotypes
Niche and Neutral Effects of Acquired Immunity Permit Coexistence of Pneumococcal Serotypes
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DOI：
10.1126/science.1215947
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发表时间：
2012-03-16
期刊：
影响因子：
56.9
通讯作者：
Lipsitch, Marc
中科院分区：
文献类型：
--
作者：
Cobey, Sarah;Lipsitch, Marc
肺炎链球菌是一种常见的鼻咽定殖菌，是肺炎、菌血症和脑膜炎的主要病因，已知有90多种荚膜血清型。目前还不清楚为什么某些血清型可以持续存在：它们更容易从载体中清除，并且在体内竞争很差。血清型特异性免疫反应，原则上可以促进多样性，但足够弱，允许相同类型的重复定殖。我们发现，弱的类特异性免疫和获得性反应不特定的胶囊可以一起重现观察到的多样性。血清型特异性免疫稳定竞争，获得性免疫非荚膜抗原减少健身差异。我们的模型可以用来解释肺炎球菌疫苗接种的影响，并指出一般因素，调节病原体的多样性。
Over 90 capsular serotypes of Streptococcus pneumoniae, a common nasopharyngeal colonizer and major cause of pneumonia, bacteremia, and meningitis, are known. It is unclear why some serotypes can persist at all: They are more easily cleared from carriage and compete poorly in vivo. Serotype-specific immune responses, which could promote diversity in principle, are weak enough to allow repeated colonizations by the same type. We show that weak serotype-specific immunity and an acquired response not specific to the capsule can together reproduce observed diversity. Serotype-specific immunity stabilizes competition, and acquired immunity to noncapsular antigens reduces fitness differences. Our model can be used to explain the effects of pneumococcal vaccination and indicates general factors that regulate the diversity of pathogens.