Identification of murine protective epitopes on the Porphyromonas gingivalis fimbrillin molecule.
Identification of murine protective epitopes on the Porphyromonas gingivalis fimbrillin molecule.
复制标题
牙龈卟啉单胞菌 fimbrillin 分子上小鼠保护性表位的鉴定。
DOI：
10.1128/iai.64.2.434-440.1996
复制
发表时间：
1996
影响因子：
3.1
通讯作者：
Flood,PM
中科院分区：
文献类型：
--
作者：
Deslauriers,M;Haque,S;Flood,PM
牙龈卟啉单胞菌的菌毛被认为在牙周病的发病机制中起重要作用。本研究的目的是确定CBA/J小鼠菌毛保护性T细胞表位。产生了对应于氨基酸1至198的截短蛋白质PgF 1 -198，并使我们能够证明该蛋白质的N末端含有T细胞表位。使用合成肽，在氨基酸103和122之间鉴定出免疫显性序列。相应的肽，PgF-P8，诱导T细胞增殖后，在体内致敏细胞的体外再刺激，得到一个刺激指数可比的r-菌毛素，并诱导生产的Th 1和Th 2细胞因子。生长上清液含有显著水平的白细胞介素2（IL-2）、γ干扰素、IL-4（28 pg/ml）和肿瘤坏死因子α。用r-菌毛蛋白、PgF 1 -198和PgF-P8免疫小鼠诱导产生对r-菌毛蛋白和PgF-P8特异性的抗体。此外，通过使用小鼠室模型，我们发现用PgF-P8免疫的小鼠显著地保护免受牙龈卟啉单胞菌的正常致死注射。在攻击前40天用PgF-P8免疫的动物在用牙龈卟啉单胞菌攻击时显示出60%的存活率，相比之下，对照动物中仅25%的存活率和在攻击前仅21天用PgF-P8免疫的小鼠中仅5%的存活率。尽管保护作用依赖于细菌攻击前的免疫时间，但它与体内局部细胞因子产生（IL-2、IL-4、IL-6、肿瘤坏死因子α和γ干扰素）、特异性抗体水平或产生的抗PgF-P8抗体的同种型无关。
Fimbriae from Porphyromonas gingivalis are believed to play an important role in the pathogenesis of periodontal diseases. The aim of the present study was to identify the fimbrial protective T-cell epitopes in CBA/J mice. A truncated protein corresponding to amino acids 1 to 198, PgF1-198, was generated and allowed us to demonstrate that the N terminus of the protein contains T-cell epitopes. With synthetic peptides, an immunodominant sequence was identified between amino acids 103 and 122. The corresponding peptide, PgF-P8, induced T-cell proliferation after in vitro restimulation of in vivo-primed cells, giving a stimulation index comparable to the one obtained with r-fimbrillin, and induced production of both Th1 and Th2 cytokines. Growth supernatant contained significant levels of interleukin 2 (IL-2), gamma interferon, IL-4 (28 pg/ml), and tumor necrosis factor alpha. Immunization of mice with r-fimbrillin, PgF1-198, and PgF-P8 induced production of antibodies specific to r-fimbrillin and PgF-P8. In addition, by using the mouse chamber model we found that mice immunized with PgF-P8 were dramatically protected against a normally lethal injection of P. gingivalis. Animals immunized with PgF-P8 40 days prior to challenge showed a 60% survival rate when challenged with P. gingivalis, compared with just 25% survival in control animals and just 5% survival in mice immunized with PgF-P8 only 21 days prior to challenge. Although the protection depended on the time of immunization before the bacterial challenge, it did not correlate with in vivo local cytokine production (IL-2, IL-4, IL-6, tumor necrosis factor alpha, and gamma interferon), specific antibody levels, or the isotype of anti-PgF-P8 antibodies produced.