Jaffe C L, Pérez M L, Sarfstein R
Department of Biophysics, Weizmann Institute of Science, Rehovot, Israel.
Exp Parasitol. 1990 Jan;70(1):12-24. doi: 10.1016/0014-4894(90)90081-m.
Species-specific monoclonal antibodies to Leishmania tropica, T11 and T13-15, recognize membranal and secreted antigens. The membrane form of the antigen migrates on sodium dodecyl sulfate-polyacrylamide gels with a diffuse molecular weight from 15 to 50 kDa and can be labeled with palmitic acid, myoinositol, galactose, glucosamine, and inorganic phosphate. Both phosphate and sugar-labeled material were isolated from metabolically labeled promastigotes by affinity chromatography on antibodies coupled to Sepharose 4B. No binding to Ricinus communis agglutinin was observed. This material behaves like lipophosphoglycans from other Leishmania but contains unique species-specific epitopes. It is susceptible to cleavage by phospholipase C and after digestion no longer partitions into the detergent phase following a Triton X-114 extraction. All four monoclonal antibodies appear to recognize a carbohydrate epitope on the lipophosphoglycan since periodate treatment of this material bound to nitrocellulose essentially eliminated antibody binding. In addition, T15 binding could be blocked by 5 mM mannose-6-PO4 and fructose-1- or 6-PO4, but not by mannose, glucose, fructose, or the additional PO4 derivatives examined. The antibodies recognize a similar but not identical epitope, as demonstrated by a competitive radioimmunoassay using 125I-labeled T11, T13, and T15. Expression of surface antigen is elevated during the promastigote stationary phase.
针对热带利什曼原虫的种特异性单克隆抗体T11和T13 - 15可识别膜抗原和分泌抗原。该抗原的膜形式在十二烷基硫酸钠 - 聚丙烯酰胺凝胶上迁移，其分子量呈弥散状，范围为15至50 kDa，并且可用棕榈酸、肌醇、半乳糖、葡糖胺和无机磷酸盐进行标记。通过与琼脂糖4B偶联的抗体进行亲和层析，从代谢标记的前鞭毛体中分离出磷酸盐和糖标记的物质。未观察到与蓖麻凝集素的结合。该物质的行为类似于来自其他利什曼原虫的脂磷酸聚糖，但含有独特的种特异性表位。它易被磷脂酶C切割，消化后经Triton X - 114萃取不再分配到去污剂相中。所有四种单克隆抗体似乎都识别脂磷酸聚糖上的碳水化合物表位，因为对与硝酸纤维素结合的该物质进行高碘酸盐处理基本上消除了抗体结合。此外，T15的结合可被5 mM甘露糖 - 6 - PO4和果糖 - 1 - 或6 - PO4阻断，但不能被甘露糖、葡萄糖、果糖或所检测的其他PO4衍生物阻断。如使用125I标记的T11、T13和T15进行的竞争性放射免疫测定所示，这些抗体识别相似但不完全相同的表位。前鞭毛体静止期表面抗原的表达升高。
