肺炎链球菌糖疫苗的研究进展

Carbohydrate-based vaccines of Streptococcus pneumoniae

摘要:

肺炎链球菌（Streptococcus pneumoniae）是引起多种疾病的主要病原体，包括侵袭性感染（如败血症和脑膜炎菌血症），以及更常见的粘膜部位感染（如肺炎、中耳炎和鼻窦炎）。根据肺炎链球菌表面荚膜多糖结构的不同可以分成不同的血清型，至今已经鉴定出98种，其中有20种具有高毒力。为了预防肺炎链球菌感染，已研制出了多种相关疫苗。目前，常用的有23价肺炎链球菌多糖疫苗（23-valent pneumococcal polysaccharide vaccine，PPV23）和13价肺炎链球菌结合疫苗（13-valent pneumococcal protein-conjugate vaccine，PCV13）。然而，从天然来源纯化的多糖抗原面临着纯化困难和组成不均等问题，因此，基于合成寡糖的糖缀合物疫苗成为一种有前途的替代物。疫苗接种后出现了血清型替代和某些血清型（如3型、19A型）致病率升高的现象，因此血清非依赖性的蛋白疫苗和全细胞疫苗成为新的研究热点。本综述主要以3型肺炎链球菌疫苗为例，概述不同种类疫苗的作用机制及其研究进展。

Abstract:

Streptococcus pneumoniae causes a range of diseases such as invasive infections (bacteremia of septicemia and meningitis, etc.) and common mucosa infections (pneumonia, otitis media, sinusitis, etc.). According to the structure of surface capsular polysaccharide, it is classified into different serotypes (98 serotypes identified, with 20 highly virulent). A number of related vaccines have been developed, among which 23-valent pneumococcal polysaccharide vaccine (PPV23) and 13-valent pneumococcal protein-conjugate vaccine (PCV13) are commonly used. However, natural polysaccharide antigens face some challenges, such as difficulty in purification and uneven composition. Therefore, synthetic oligosaccharide-based glycoconjugate vaccines have become a promising alternative. After vaccination, serotype substitution occurs and the pathogenicity rate of certain serotypes (such as serotype 3 and 19A) increases. Thus, serum-independent protein vaccines and whole-cell vaccines have become a new research focus. This review took S. pneumoniae serotype 3 vaccine as an example to summarize the mechanism of different types of vaccines and their research progress.