Di-Blasi Tatiana, Lobo Amanda R, Nascimento Luanda M, Córdova-Rojas Jose L, Pestana Karen, Marín-Villa Marcel, Tempone Antonio J, Telleria Erich L, Ramalho-Ortigão Marcelo, McMahon-Pratt Diane, Traub-Csekö Yara M
1 Laboratório de Biologia Molecular de Parasitas e Vetores, Instituto Oswaldo Cruz , FIOCRUZ, Rio de Janeiro, RJ, Brazil .
Vector Borne Zoonotic Dis. 2015 Mar;15(3):202-9. doi: 10.1089/vbz.2014.1736.
Leishmaniasis is a serious problem that affects mostly poor countries. Various species of Leishmania are the agents of the disease, which take different clinical manifestations. The parasite is transmitted by sandflies, predominantly from the Phlebotomus genus in the Old World and Lutzomyia in the New World. During development in the gut, Leishmania must survive various challenges, which include avoiding being expelled with blood remnants after digestion. It is believed that attachment to the gut epithelium is a necessary step for vector infection, and molecules from parasites and sand flies have been implicated in this attachment. In previous work, monoclonal antibodies were produced against Leishmania. Among these an antibody was obtained against Leishmania braziliensis flagella, which blocked the attachment of Leishmania panamensis flagella to Phlebotomus papatasi guts. The protein recognized by this antibody was identified and named FLAG1, and the complete FLAG1 gene sequence was obtained. This protein was later independently identified as a small, myristoylated protein and called SMP1, so from now on it will be denominated FLAG1/SMP1. The FLAG1/SMP1 gene is expressed in all developmental stages of the parasite, but has higher expression in promastigotes. The anti-FLAG1/SMP1 antibody recognized the flagellum of all Leishmania species tested and generated the expected band by western blots. This antibody was used in attachment and infection blocking experiments. Using the New World vector Lutzomyia longipalpis and Leishmania infantum chagasi, no inhibition of attachment ex vivo or infection in vivo was seen. On the other hand, when the Old World vectors P. papatasi and Leishmania major were used, a significant decrease of both attachment and infection were seen in the presence of the antibody. We propose that FLAG1/SMP1 is involved in the attachment/infection of Leishmania in the strict vector P. papatasi and not the permissive vector L. longipalpis.
利什曼病是一个主要影响贫穷国家的严重问题。多种利什曼原虫是该疾病的病原体，会呈现不同的临床表现。这种寄生虫通过白蛉传播，在旧世界主要由白蛉属传播，在新世界则由罗蛉属传播。在肠道发育过程中，利什曼原虫必须应对各种挑战，其中包括避免在消化后随血液残渣被排出体外。据信，附着于肠道上皮是载体感染的必要步骤，寄生虫和白蛉的分子都与这种附着有关。在之前的工作中，制备了针对利什曼原虫的单克隆抗体。其中一种抗体是针对巴西利什曼原虫鞭毛产生的，它能阻断巴拿马利什曼原虫鞭毛与巴氏白蛉肠道的附着。鉴定出了被该抗体识别的蛋白质并将其命名为FLAG1，还获得了完整的FLAG1基因序列。该蛋白质后来被独立鉴定为一种小的、豆蔻酰化的蛋白质，并被称为SMP1，所以从现在起将其命名为FLAG1/SMP1。FLAG1/SMP1基因在寄生虫的所有发育阶段都有表达，但在前鞭毛体中表达较高。抗FLAG1/SMP1抗体识别所有测试的利什曼原虫物种的鞭毛，并通过蛋白质免疫印迹产生预期条带。该抗体用于附着和感染阻断实验。使用新世界载体长须罗蛉和婴儿利什曼原虫恰加斯亚种时，未观察到体外附着或体内感染受到抑制。另一方面，当使用旧世界载体巴氏白蛉和硕大利什曼原虫时，在抗体存在的情况下，附着和感染均显著降低。我们认为FLAG1/SMP1参与了利什曼原虫在严格载体巴氏白蛉而非宽容载体长须罗蛉中的附着/感染过程。
