Department of Microbiology, University of Chicago, 920 East 58th Street, Chicago, IL 60637, USA.
Vaccine. 2010 Feb 17;28(7):1870-6. doi: 10.1016/j.vaccine.2009.11.076. Epub 2009 Dec 10.
LcrV, a protein that resides at the tip of the type III secretion needles of Yersinia pestis, is the single most important plague protective antigen. Earlier work reported monoclonal antibody MAb 7.3, which binds a conformational epitope of LcrV and protects experimental animals against lethal plague challenge. By screening monoclonal antibodies directed against LcrV for their ability to protect immunized mice against bubonic plague challenge, we examined here the possibility of additional protective epitopes. MAb BA5 protected animals against plague, neutralized the Y. pestis type III secretion pathway and promoted opsonophagocytic clearance of bacteria in blood. LcrV residues 196-225 were necessary and sufficient for MAb BA5 binding. Compared to full-length LcrV, a variant lacking its residues 196-225 retained the ability of eliciting plague protection. These results identify LcrV residues 196-225 as a linear epitope that is recognized by the murine immune system to confer plague protection.
LcrV 是鼠疫耶尔森氏菌 III 型分泌针顶端的一种蛋白质，是唯一最重要的鼠疫保护抗原。早期的工作报道了单克隆抗体 MAb 7.3，它结合了 LcrV 的构象表位，并保护实验动物免受致命的鼠疫挑战。通过筛选针对 LcrV 的单克隆抗体，研究其保护免疫小鼠免受鼠疫挑战的能力，我们在这里研究了其他保护性表位的可能性。MAb BA5 可保护动物免受鼠疫感染，中和鼠疫耶尔森氏菌的 III 型分泌途径，并促进血液中细菌的调理吞噬清除。MAb BA5 结合所必需和充分的是 LcrV 残基 196-225。与全长 LcrV 相比，缺乏残基 196-225 的变体保留了引发鼠疫保护的能力。这些结果表明 LcrV 残基 196-225 是一个线性表位，被小鼠免疫系统识别以赋予鼠疫保护。
