合成衣原体属特异LPS决定簇糖结合物的抗原性分析

Antigenicity of a Synthetic Glycoconjugate Representing the Genus-Specific Epitope of Chlamydial Lipopolysaccharide

合成衣原体属特异脂多糖（ＬＰＳ）的四糖链α－２－酮基－３－脱氧辛酸（ＫＤＯ）（２→８）－α－ＫＤＯ（２→４）－α－ＫＤＯ（２→６）－β－ＧｌｃＮＡｃ与牛血清白蛋白（ＢＳＡ）共价结合，制成糖－ＢＳＡ结合物抗原，用其免疫小鼠所制备的单克隆抗体（ＭｃＡｂ）经间接血凝试验、血凝抑制试验、ＥＬＩＳＡ、免疫荧光试验和免疫印渍等试验分析，结果把这些ＭｃＡｂ分为两组：一组与衣原体ＬＰＳ和Ｒｅ型ＬＰＳ有交叉反应；另一组为衣原体特异性抗体，其中ＫＤＯ３特异抗体与衣原体原体ＭｃＡｂ有共同决定簇特异性，但亲和力却高于后者１００多倍。表明合成糖－ＢＳＡ结合物与衣原体ＬＰＳ有相似的抗原性。

The tetrasaccharide 2-keto-3-deoxy-octonic acid (α-KDO)(2→8)-α -KDO (2→4)-α-KDO(2→6)-βGlcNAc,a partial structure of chlamydial lipopolysaccharide(LPS)representing a genus-specificepitope,was synthesized and covalently linked to bovine serum albmin,resulting in an artificial glyco-conjugate antigen. Mice were immunized with the glycoconjugate to prepare chamydia-specifiC monco-clonal antibodies.Characterization of the selected antibodies was by(1) passive hemaggltitination,(2)inhibition of hemagglutination,(3)ELISA,(4)imunofluorescence assay and(5)Western im-munoblots. Two groups of monoclonal antibodies were obtained;the monoclonal antibodies in onegroup cross-reacted with chlamydial and Re-type LPS,but those of the other group were chlamydiaspecifc. A mong the latter,KDO trisaccharide-specific antibodies that had the same epitope specificityas antibodies obtained after immunization with chlamydial elementary bodies were identified:howev-er,they exhibited a more than 100-fold higher affinity. The data show that the artificial glycoconju-gate antigen is Similar to its natural counterpart in the immunogenicity and antigenicity.