Simpson W J, Thomas R E, Schwan T G
National Institute of Allergy and Infectious Diseases, Rocky Mountain Laboratories, Hamilton, Montana.
Am J Trop Med Hyg. 1990 Oct;43(4):389-96. doi: 10.4269/ajtmh.1990.43.389.
Yersinia pestis produces a glycoprotein capsule, the biosynthesis of which appears to be temperature dependent. The fraction I (F1) component of this capsule is specific to Y. pestis and the detection of F1 antibodies is the basis for several serological tests. We report the cloning of the F1 gene and its expression in Escherichia coli using the phagemid vector lambda ZAPII and a F1-specific monoclonal antibody. The recombinant F1 antigen had a molecular weight of 17 kDa, which proved to be identical to that of the F1 antigen produced by Y. pestis. The recombinant cells produced F1 antigen at 37 degrees C but only minimal amounts at 27 degrees C, suggesting that the genetic features affected by temperature in Y. pestis may be operating in the E. coli clone. It is not known if their similar molecular weights reflect the glycosylated nature of both proteins. F1 antigen purified from the E. coli recombinant induced a protective immune response in BALB/c mice challenged with up to 10(5) virulent Y. pestis. The resistance of immunized mice to plague infection correlated with high titers of F1 antibody. The cloned gene expresses an immunogenically competent F1 antigen suitable for use in plague serodiagnostics and vaccine development.
鼠疫耶尔森菌产生一种糖蛋白荚膜，其生物合成似乎依赖于温度。该荚膜的I组分（F1）是鼠疫耶尔森菌特有的，F1抗体的检测是几种血清学检测的基础。我们报道了利用噬菌粒载体λZAPII和F1特异性单克隆抗体克隆F1基因并在大肠杆菌中表达。重组F1抗原的分子量为17 kDa，与鼠疫耶尔森菌产生的F1抗原相同。重组细胞在37℃时产生F1抗原，但在27℃时仅产生极少量，这表明鼠疫耶尔森菌中受温度影响的遗传特性可能在大肠杆菌克隆中起作用。尚不清楚它们相似的分子量是否反映了两种蛋白质的糖基化性质。从大肠杆菌重组体中纯化的F1抗原在用高达10^5毒力的鼠疫耶尔森菌攻击的BALB/c小鼠中诱导了保护性免疫反应。免疫小鼠对鼠疫感染的抵抗力与高滴度的F1抗体相关。克隆的基因表达了一种免疫原性活性的F1抗原，适用于鼠疫血清诊断和疫苗开发。
