Pneumococcal surface adhesin A (PsaA) is a surface-exposed common 37-kilodalton multi-functional lipoprotein detected on all known serotypes of Streptococcus pneumoniae. This lipoprotein belongs to the ABC-type transport protein complex that transports Mn(2+); it is also an adhesin that plays a major role in pneumococcal attachment to the host cell and virulence. PsaA is immunogenic and natural nasopharyngeal colonization of pneumococci elicits an increase in antibody towards PsaA. Hence, PsaA is being actively evaluated as a component of a vaccine in formulations composed of pneumococcal common proteins. PsaA has been expressed as an E. coli recombinant protein, purified, and evaluated in a phase one clinical trial. This article reviews PsaA, its structure and role in pneumococcal virulence, immunogenicity, and potential to reduce nasopharyngeal colonization (a major prerequisite for pneumococcal pathogenesis) as a component of a common pneumococcal protein vaccine.

中文翻译：

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肺炎球菌表面粘附素A（PsaA）：综述。

肺炎球菌表面粘附素A（PsaA）是在肺炎链球菌的所有已知血清型中检测到的表面暴露的常见37-千达尔顿多功能脂蛋白。这种脂蛋白属于转运Mn（2+）的ABC型转运蛋白复合物；它也是一种粘附素，在肺炎球菌对宿主细胞的附着和毒力中起主要作用。PsaA是免疫原性的，肺炎球菌的天然鼻咽定殖会引起针对PsaA的抗体增加。因此，正在积极评估PsaA作为由肺炎球菌常见蛋白组成的制剂中疫苗的组成部分。PsaA已被表达为一种大肠杆菌重组蛋白，已经过纯化，并在一项临床试验中进行了评估。本文回顾了PsaA，其结构和在肺炎球菌毒力，免疫原性，