Unité de Biologie et Génétique du Paludisme, Institut Pasteur, 75724 Paris Cedex 15, France.
Proc Natl Acad Sci U S A. 2010 Oct 26;107(43):18640-5. doi: 10.1073/pnas.1009346107. Epub 2010 Oct 4.
The first step of Plasmodium development in vertebrates is the transformation of the sporozoite, the parasite stage injected by the mosquito in the skin, into merozoites, the stage that invades erythrocytes and initiates the disease. The current view is that, in mammals, this stage conversion occurs only inside hepatocytes. Here, we document the transformation of sporozoites of rodent-infecting Plasmodium into merozoites in the skin of mice. After mosquito bite, ∼50% of the parasites remain in the skin, and at 24 h ∼10% are developing in the epidermis and the dermis, as well as in the immunoprivileged hair follicles where they can survive for weeks. The parasite developmental pathway in skin cells, although frequently abortive, leads to the generation of merozoites that are infective to erythrocytes and are released via merosomes, as typically observed in the liver. Therefore, during malaria in rodents, the skin is not just the route to the liver but is also the final destination for many inoculated parasites, where they can differentiate into merozoites and possibly persist.
疟原虫在脊椎动物体内的发育第一步是将疟原虫孢子转化为裂殖子，疟原虫孢子是由蚊子在皮肤中注射的寄生虫阶段，转化为裂殖子，裂殖子阶段侵入红细胞并引发疾病。目前的观点是，在哺乳动物中，这种阶段转换仅在肝细胞内发生。在这里，我们记录了啮齿动物感染的疟原虫孢子在小鼠皮肤中转化为裂殖子的过程。在蚊子叮咬后，约有 50%的寄生虫仍留在皮肤中，在 24 小时内，约有 10%的寄生虫在表皮和真皮以及免疫特权的毛囊中发育，在那里它们可以存活数周。皮肤细胞中的寄生虫发育途径虽然经常中断，但会导致裂殖子的产生，裂殖子对红细胞具有感染性，并通过merosomes 释放，这与通常在肝脏中观察到的情况类似。因此，在啮齿动物疟疾期间，皮肤不仅是进入肝脏的途径，也是许多接种的寄生虫的最终目的地，在那里它们可以分化为裂殖子并可能持续存在。
