Simonetti A B, Billingsley P F, Winger L A, Sinden R E
Department of Biology, Imperial College of Science, Technology and Medicine, London, United Kingdom.
J Eukaryot Microbiol. 1993 Sep-Oct;40(5):569-76. doi: 10.1111/j.1550-7408.1993.tb06109.x.
Expression of a 21 kDa determinant (Pbs21), first detected on the surface of ookinetes, and of the circumsporozoite protein (CSP) was studied by immunofluorescence and Western blots during the developmental cycle of Plasmodium berghei in the mosquito Anopheles stephensi. The expression of Pbs21 was predominantly localised on the ookinete surface one day after the infectious blood meal, and thereafter reactivity declined to a minimum on days 2 and 3, the time of onset of oocyst development. A gradual increase in fluorescence was observed on the oocysts from day 6 that was retained until day 17 post-infection. In contrast, sporozoites released from oocysts or salivary glands showed little or no antibody labelling with anti-Pbs21. Circumsporozoite protein was not detectable in any midgut preparations until 5-6 days after feeding, when reactivity was observed against immature oocysts. Expression then continued and increased throughout oocyst and sporozoite development. Western blots confirmed that Pbs21 was expressed minimally during the oocyst development but was not detectable in sporozoites. Co-localisation of anti-Pbs21 and anti-CSP monoclonal antibodies to the 50 kDa and 60 kDa bands in Western blots of sporozoite suggests immunological cross-reactivity between the CSP and the anti-21 kDa antibodies.
在斯氏按蚊体内伯氏疟原虫的发育周期中，通过免疫荧光和蛋白质免疫印迹法研究了最初在动合子表面检测到的21 kDa决定簇（Pbs21）和环子孢子蛋白（CSP）的表达情况。感染性血餐一天后，Pbs21的表达主要定位于动合子表面，此后在第2天和第3天，即卵囊开始发育时，反应性降至最低。从感染后第6天开始，在卵囊上观察到荧光逐渐增加，并一直持续到感染后第17天。相比之下，从卵囊或唾液腺释放的子孢子用抗Pbs21抗体几乎没有或没有抗体标记。在喂食后5 - 6天之前，任何中肠制剂中都检测不到环子孢子蛋白，此时观察到对未成熟卵囊的反应性。然后在整个卵囊和子孢子发育过程中表达持续并增加。蛋白质免疫印迹证实，Pbs21在卵囊发育期间表达极少，但在子孢子中检测不到。在子孢子的蛋白质免疫印迹中，抗Pbs21和抗CSP单克隆抗体与50 kDa和60 kDa条带的共定位表明CSP与抗21 kDa抗体之间存在免疫交叉反应。
