Effects of polymorphism of HLA on binding of antigenic peptides to HLA and recognition of peptides complexed with HLA by T cell receptor

HLA多态性对抗原肽与HLA结合及T细胞受体识别HLA复合肽的影响

基本信息

批准号：
03452276
负责人：
NISHIMURA Yasuharu
金额：
$ 4.35万
依托单位：
Kumamoto University School of Medicine (1992-1993)Kyushu University (1991)
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

项目摘要

HLA-DR molecules are highly polymorphic molecules and bind antigenic peptides to present it to CD4 positive helper T cells. The particular DR alleles are thought to determine susceptibility to autoimmune diseases because the frequencies of particular DR allelse are increased in the patients group as compared with those in healthy controls. Thus DRB1 ^<**>0405 and DRB1 ^<**>0406 which differs in only four amino acid residues from DRB1 ^<**>0405 control susceptibility to rheumatoid arthritis and insulin autoimmune syndrome respectively. We have investigated the structural characteristics of antigenic peptides bound to either DRB1 ^<**>0405 or DRB1 ^<**>0406 molecules. For this aim, self peptides bound to purified DRB1 ^<**>0405 molecules were isolated and fractionated by a reversed phase HPLC.Amino acid sequences of seven independent peptides were determined and four of them were identified to be fragments of known proteins. These self peptides were synthesized and radio-iodinated, and binding of labeled peptides to DR molecules were investigated. The strongest binder among seven self peptides was identified and this peptide bound to both DRB1 ^<**>0405 and DRB1 ^<**>0406 equally. The binding inhibition assay, in which binding activity of a peptide to be tested was determined by measuring inhibitory effect of the excess amount of peptide on binding of the labeled strongest binder to DR molecule, was established. In order to determine amino acid residues important for DR binding in the strongest binder, analogue peptides having only one amino acid substitution from the original peptides were synthesized and their binding to both DRB1 ^<**>0405 and DRB1 ^<**>0406 was investigated. DR binding peptides consisted of nine to twenty amino acids were bound at three major anchorage amino acid residues of the peptide to DR molecule. These three anchorage residues were separated by two and one intervening amino acids. The first

HLA-DR分子是高度多态分子，并结合抗原肽，将其呈现为CD4阳性辅助T细胞。人们认为特定的DR等位基因确定了对自身免疫性疾病的敏感性，因为与健康对照组相比，患者组的特定DR Allelse的频率增加。因此，DRB1 ^<**> 0405和DRB1 ^<**> 0406，仅在四个氨基酸残基与DRB1 ^<**> 0405中有不同的不同，分别控制对类风湿关节炎和胰岛素自身免疫性综合征的敏感性。我们已经研究了与DRB1 ^<**> 0405或DRB1 ^<**> 0406分子结合的抗原肽的结构特性。为此，分离了与纯化的DRB1 ^<**> 0405分子的自肽分离，并通过反向相位的HPLC分离。确定了七个独立肽的氨基酸序列，并确定了四个是已知蛋白质的片段。这些自肽是合成的，并通过射线固定，并研究了标记的肽与DR分子的结合。鉴定出七个自肽中最强的粘合剂，并且该肽均与Drb1 ^<**> 0405和Drb1 ^<**> 0406绑定。通过测量过量肽对标记的最强粘合剂与DR Molecule的最强粘合剂结合的抑制作用来确定要测试的肽的结合活性的结合抑制测定。为了确定对最牢固粘合剂中DR结合重要的氨基酸残基，合成了只有一种来自原始肽的氨基酸取代的模拟肽，并合成了与Drb1 ^<**> 0405和DRB1 ^<**> 0406的结合被调查。 DR结合肽由9至20个氨基酸组成，在肽的三个主要锚固氨基酸残基上与DR分子结合。这三个锚固残基由两个和一个中间的氨基酸分离。第一个