Synthetic Human Monoclonal Antibodies toward Staphylococcal Enterotoxin B (SEB) Protective against Toxic Shock Syndrome
Synthetic Human Monoclonal Antibodies toward Staphylococcal Enterotoxin B (SEB) Protective against Toxic Shock Syndrome
复制标题
DOI：
10.1074/jbc.m112.364075
复制
发表时间：
2012-07-20
影响因子：
4.8
通讯作者：
Aman, M. Javad
中科院分区：
文献类型：
--
作者：
Karauzum, Hatice;Chen, Gang;Aman, M. Javad
葡萄球菌肠毒素B（SE B）是一种强效毒素，可引起中毒性休克综合征，并在用作生物武器时作为致死和失能剂。目前还没有针对这种毒素的疫苗或免疫治疗剂。使用噬菌体展示技术，人的抗原结合片段（Fab）选择对SEB，蛋白质在大肠杆菌细胞中产生，其特征在于它们的结合亲和力和毒素中和活性在体外和体内。高度保护性的Fab被转化为全长IgG并在哺乳动物细胞中产生。此外，在本氏烟草植物表达系统中探索了抗SEB抗体的产生。进行亲和力成熟以产生具有亚纳摩尔亲和力的优化的前导抗SEB抗体候选物。N. benthamiana显示出与哺乳动物细胞中产生的对应物相当的特征。在小鼠中毒性休克模型中，使用不同攻击剂量的SEB和在SEB攻击后1小时用200 μ g IgG处理，测试IgG的治疗功效。在广泛的SEB攻毒剂量范围内，主要候选物显示出对致死攻毒的完全保护。此外，与模拟治疗的小鼠相比，用抗SEB IgG治疗的小鼠血清中的IFN γ和IL-2水平显著降低。总之，这些抗SEB单克隆抗体代表了进一步临床前和临床开发的优秀治疗候选物。
Staphylococcal enterotoxin B (SEB) is a potent toxin that can cause toxic shock syndrome and act as a lethal and incapacitating agent when used as a bioweapon. There are currently no vaccines or immunotherapeutics available against this toxin. Using phage display technology, human antigen-binding fragments (Fabs) were selected against SEB, and proteins were produced in Escherichia coli cells and characterized for their binding affinity and their toxin neutralizing activity in vitro and in vivo. Highly protective Fabs were converted into full-length IgGs and produced in mammalian cells. Additionally, the production of anti-SEB antibodies was explored in the Nicotiana benthamiana plant expression system. Affinity maturation was performed to produce optimized lead anti-SEB antibody candidates with subnanomolar affinities. IgGs produced in N. benthamiana showed characteristics comparable with those of counterparts produced in mammalian cells. IgGs were tested for their therapeutic efficacy in the mouse toxic shock model using different challenge doses of SEB and a treatment with 200 mu g of IgGs 1 h after SEB challenge. The lead candidates displayed full protection from lethal challenge over a wide range of SEB challenge doses. Furthermore, mice that were treated with anti-SEB IgG had significantly lower IFN gamma and IL-2 levels in serum compared with mock-treated mice. In summary, these anti-SEB monoclonal antibodies represent excellent therapeutic candidates for further preclinical and clinical development.