FREQUENCY OF VARIANT ANTIGENS IN GIARDIA-LAMBLIA
FREQUENCY OF VARIANT ANTIGENS IN GIARDIA-LAMBLIA
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DOI：
10.1016/0014-4894(90)90067-m
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发表时间：
1990-11-01
影响因子：
2.1
通讯作者：
CONRAD, JT
中科院分区：
文献类型：
--
作者：
NASH, TE;BANKS, SM;CONRAD, JT
蓝氏贾第鞭毛虫经历抗原变异。在蓝氏贾第鞭毛虫克隆中估计抗原变异率和变异抗原库的大小，蓝氏贾第鞭毛虫克隆重新表达其亲本的特征表面变异抗原。计算基于表达确定或未确定表位的滋养体数量以及新建立的克隆中滋养体的总数的测定。含有确定表位的变体抗原的出现率表示为直到第一个表达确定表位的滋养体出现的代数。在分离株WB的克隆中，由于其主要表面变体抗原在很大程度上是未定义的，因此进行了测试，表达由Mab 6 E7或3F 6识别的表位的变体在大约12代后出现。表达Mab 5C 1识别的表位的变体出现在约13代，显著大于其他表位。在另一个分离株GS/M中研究了抗原变异率，GS/M的表面表位库不同于分离株WB。测试由Mab G10/4识别的单个表位。滋养体重新表达该表位首次出现后约6.5代，显着低于WB。因此，在分离物GS/M中研究的单个表位比WB中的表位更频繁地再表达。在WB株中，6 E7和3F 6识别的表位有同时出现的趋势。WB中变异抗原的中位数估计在20.5和184之间。
Giardia lamblia undergoes antigenic variation. The rate of antigenic variation and the size of the variant antigen repertoire were estimated in clones of Giardia lamblia which reexpresses surface variant antigens that are characteristics of its parent. Calculations were based on determinations of the number of trophozoites expressing defined or nondefined epitopes as well as the total number of trophozoites in newly established clones. The rate of appearance of variant antigens containing defined epitopes was expressed as the number of generations until the first trophozoite expressing a defined epitope appeared. In clones of isolate WB, tested because their major surface variant antigens were largely nondefined, variants expressing epitopes recognized by Mabs 6E7 or 3F6 appeared after approximately 12 generations. Variants expressing epitopes recognized by Mab 5C1 appeared at about 13 generations, significantly greater than for the other epitopes. The rate of antigenic variation was studied in another isolate, GS/M, whose surface epitope repertoire differs from that of isolate WB. A single epitope recognized by Mab G10/4 was tested. Trophozoites reexpressing this epitope first appeared after about 6.5 generations, significantly less than in WB. Therefore, the single epitope studied in isolate GS/M is reexpressed much more frequently than those of WB. In isolate WB, the epitopes recognized by Mab 6E7 and 3F6 tended to appear at the same time. The median number of variant antigens in WB was estimated to lie between 20.5 and 184.