Beghetto Elisa, Gargano Nicola, Ricci Susanna, Garufi Gabriella, Peppoloni Samuele, Montagnani Francesca, Oggioni Marco, Pozzi Gianni, Felici Franco
Kenton Srl, Pomezia, Rome, Italy.
FEMS Microbiol Lett. 2006 Sep;262(1):14-21. doi: 10.1111/j.1574-6968.2006.00360.x.
Streptococcus pneumoniae is a causative agent of otitis media, pneumonia, meningitis and sepsis in humans. For the development of effective vaccines able to prevent pneumococcal infection, characterization of bacterial antigens involved in host immune response is crucial. In order to identify pneumococcal proteins recognized by host antibody response, we created an S. pneumoniae D39 genome library, displayed on lambda bacteriophage. The screening of such a library, with sera either from infected individuals or mice immunized with the S. pneumoniae D39 strain, allowed identification of phage clones carrying S. pneumoniae B-cell epitopes. Epitope-containing fragments within the families of the histidine-triad proteins (PhtE, PhtD), the choline-binding proteins (PspA, CbpD) and zinc metalloproteinase B (ZmpB) were identified. Moreover, library screening also allowed the isolation of phage clones carrying three distinct antigenic regions of a hypothetical pneumococcal protein, encoded by the ORF spr0075 in the R6 strain genome sequence. In this work, Spr0075 is first identified as an expressed S. pneumoniae gene product, having an antigenic function during infection.
肺炎链球菌是人类中耳炎、肺炎、脑膜炎和败血症的病原体。对于开发能够预防肺炎球菌感染的有效疫苗而言，鉴定参与宿主免疫反应的细菌抗原至关重要。为了鉴定宿主抗体反应所识别的肺炎球菌蛋白，我们构建了一个展示在λ噬菌体上的肺炎链球菌D39基因组文库。用来自感染个体或用肺炎链球菌D39菌株免疫的小鼠的血清筛选这样的文库，能够鉴定携带肺炎链球菌B细胞表位的噬菌体克隆。在组氨酸三联体蛋白家族（PhtE、PhtD）、胆碱结合蛋白家族（PspA、CbpD）和锌金属蛋白酶B（ZmpB）中鉴定出了含表位的片段。此外，文库筛选还使得携带由R6菌株基因组序列中的开放阅读框spr0075编码的一种假定肺炎球菌蛋白的三个不同抗原区域的噬菌体克隆得以分离。在这项研究中，Spr0075首次被鉴定为一种表达的肺炎链球菌基因产物，在感染过程中具有抗原功能。
