Identification of antigenic epitope for neutralizing antibody that inhibits enzymatic activity of Helicobacter pylori urease

抑制幽门螺杆菌脲酶酶活性的中和抗体抗原表位的鉴定

基本信息

批准号：
13670481
负责人：
TAKAHASHI Hidemi
金额：
$ 2.18万
依托单位：
Nippon Medical School
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13670481/
关键词：
Helicobacter pylori urease neutralizing antibody epitope MAP mapping vaccine enzymatic activity Helicobacter pylori vaccine Hybridoma エピトープ合成ペプチド

项目摘要

There may be two types of Helicobacter pylori (H.pylori) urease-specific antibodies, one is unfavorable to the body in progressing gastritis and the other is benefical in preventing bacterial growth and attachment to the gastric mucosa. To find the epitope for the latter type, a series of overlapping peptides were synthesized to identify the epitope of a mouse monoclonal antibody (mAb), termed L2, which has the capacity to generate complete suppression of the enzymatic activity of H. pylori urease. Among 79 overlapping peptides tested, a predominant epitope, UB-33 (aa 321-339; CHHLDKSIKEDVQFADSRI), was identified. Immunization with KLH-conjugated UB-33 induced UB-33-specific antibody which partially abrogated the urease activity. The minimal epitope of L2 was F8 (SIKEDVQF), whereas 6-mer peptide (KEDVQF) was the minimum for UB-33-specific rabbit sera. F8-based multiple antigenic peptides (MAP) generated UB-33-specific antibody that was much stronger than UB-33 but less potent than L2 and its minimal epitope was 6-mer (SIKEDV). The amino acid 329K seems to be critical to the L2-specific antibody response. The findings shown here provide important information on making a neutralizing vaccine to prevent H.pylori infection as well as its persistency in the stomach.

可能有两种类型的幽门螺杆菌（幽门螺杆菌）尿素酶特异性抗体，一种对正在进行的胃炎中的身体不利，另一种是防止细菌生长和对胃粘膜的附着的好处。为了找到后一种类型的表位，合成了一系列重叠的肽，以识别称为L2的小鼠单克隆抗体（MAB）的表位，该肽具有L2的能力，该抗体具有完全抑制幽门螺杆菌的H.得期的酶活性。在测试的79个重叠肽中，鉴定了一个主要的表位UB-33（AA 321-339； Chhldksikedvqfadsri）。用KLH偶联的UB-33诱导的UB-33特异性抗体免疫，该抗体部分废除了尿素酶活性。 L2的最小表位为F8（SikedVQF），而6-Mer肽（KEDVQF）是UB-33特异性兔血清的最小值。基于F8的多种抗原肽（MAP）产生的UB-33特异性抗体比UB-33强得多，但比L2强得多，其最小表位是6-mer（SikeDV）。氨基酸329K似乎对L2特异性抗体反应至关重要。此处显示的发现提供了有关制作中和疫苗以防止幽门螺杆菌感染及其在胃中的持久性的重要信息。