Antigenic variation of Giardia lamblia in experimental human infections.
Antigenic variation of Giardia lamblia in experimental human infections.
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实验性人类感染中兰氏贾第鞭毛虫的抗原变异。
DOI：
10.4049/jimmunol.144.11.4362
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发表时间：
1990
影响因子：
4.4
通讯作者：
J. W. Merritt
中科院分区：
文献类型：
--
作者：
T. Nash;D. Herrington;M. Levine;J. Conrad;J. W. Merritt
为了确定贾第鞭毛虫表面抗原在人类感染中是否不同，志愿者用未克隆的GS/M-85滋养体肠内接种，并在随后的实验中用来自GS/M的两个克隆接种。从6/6名志愿者中重新分离的滋养体表面Ag与接种物不同。为了确定来自克隆的滋养体的表面Ag是否也会改变，志愿者接种了两个克隆B6或H7。B6具有由mAb 3F 6识别的200-kDa表面Ag，H7具有由mAb G10/4识别的72-kDa表面Ag。13名接种B6疫苗的志愿者中有1人感染，4名接种H7疫苗的志愿者中有4人感染。对第22天从4名H7感染的志愿者的肠中获得的贾第虫和来源于这些滋养体的培养物的分析显示，如通过使用mAb的表面IFA、表面放射性标记和对mAb的细胞毒性的损失以及蛋白质印迹所确定的，初始主要表面Ag的损失。72 kDa Ag的损失在第14天后开始，到第22天几乎完全。200 kDa的表面Ag几乎完全不存在从单个B6感染的志愿者分离的贾第虫的表面。血清表面反应性抗体，通过IFA和细胞毒性测定H7和第22天的分离株，表现出高水平的抗体H7，主要是72 kDa的表面抗原，但可以忽略不计或低水平的后期出现的抗体的第22天的分离株。这些研究记录了贾第虫在人类感染中的抗原变异，并表明体液应答部分是分离株特异性的。
To determine if Giardia surface Ag vary in human infections volunteers were inoculated enterally with trophozoites of uncloned GS/M-85 and in later experiments with two clones derived from GS/M. The surface Ag of trophozoites reisolated from 6/6 volunteers differed from the inoculum. To determine if the surface Ag of trophozoites derived from clones would also change, volunteers were inoculated with two clones, B6 or H7. B6 possesses a 200-kDa surface Ag recognized by mAb 3F6 and H7 has a 72-kDa surface Ag recognized by mAb G10/4. One of thirteen B6 and four of four H7-inoculated volunteers became infected. Analysis of Giardia obtained on day 22 from the intestines of the four H7-infected volunteers and cultures derived from these trophozoites revealed loss of the initial major surface Ag as determined by surface IFA using mAb, surface radiolabeling and loss of cytotoxicity to mAb, and Western blots. Loss of the 72-kDa Ag began after day 14 and was practically complete by day 22. The 200-kDa surface Ag was almost totally absent from the surface of Giardia isolated from the single B6-infected volunteer. Serum surface-reactive antibodies, as measured by IFA and cytotoxicity to H7 and the day 22 isolates, showed high levels of antibodies to H7, primarily to the 72-kDa surface Ag, but negligible or low levels of late-appearing antibodies to the day 22 isolates. These studies document antigenic variation of Giardia in human infections and show that humoral responses are in part isolate-specific.