Department of Animal Biology, Faculty of Sciences, Damascus University, Damascus, Syria.
Division of Molecular Biomedicine, Department of Molecular Biology and Biotechnology, AECS, Damascus, Syria.
Parasite Immunol. 2020 Sep;42(9):e12718. doi: 10.1111/pim.12718. Epub 2020 Jul 14.
To characterize several anti-Leishmania tropica nanobodies and to investigate their effect on Leishmania infection.
Several immunological tests were implied to characterize five different (as confirmed by sequencing) anti-L tropica nanobodies (NbLt05, NbLt06, NbLt14, NbLt24 and NbLt36) against parasite lysates or intact cells from different stages, promastigotes and amastigotes. Direct inhibitory effect of these nanobodies on parasite infection cycle on macrophages was tested in cell culture.
All the five nanobodies (with distinguished characteristics) were more specific to L tropica than to L major, but could equally recognize the lysate and the outer surface of the intact cells from the two main stages of the parasite. Nanobodies recognized several leishmania antigens (majorly between 75 and 63 kDa), and their proteinaceous nature was confirmed. Because of its role in leishmania life cycle, gp63 was considered a potential antigen candidate for nanobodies, and bioinformatics predicted such interaction. All nanobodies have a negative effect on the infectivity of L tropica, as they decreased the number of infected macrophages and the amastigotes inside those macrophages.
Such anti-leishmania nanobodies, with outstanding characteristics and important target, can be of great use in the development of promising treatment strategies against leishmaniasis.
鉴定几种抗利什曼原虫热带株的纳米抗体并研究其对利什曼原虫感染的影响。
通过多种免疫试验鉴定了 5 种不同的（经测序证实）抗利什曼原虫热带株的纳米抗体（NbLt05、NbLt06、NbLt14、NbLt24 和 NbLt36），这些纳米抗体针对的是寄生虫裂解物或不同阶段、前鞭毛体和无鞭毛体的完整细胞。在细胞培养中测试了这些纳米抗体对巨噬细胞中寄生虫感染周期的直接抑制作用。
所有 5 种纳米抗体（具有不同的特征）对利什曼原虫热带株的特异性均高于利什曼原虫麦氏亚种，但均能同等识别两种主要阶段寄生虫的裂解物和完整细胞的外表面。纳米抗体识别了几种利什曼原虫抗原（主要在 75-63 kDa 之间），并证实了其蛋白性质。由于 gp63 在利什曼原虫生命周期中的作用，gp63 被认为是纳米抗体的潜在抗原候选物，生物信息学预测了这种相互作用。所有纳米抗体均对利什曼原虫热带株的感染力产生负面影响，因为它们减少了感染巨噬细胞的数量和这些巨噬细胞内的无鞭毛体。
这些具有突出特征和重要靶标的抗利什曼原虫纳米抗体，可在开发针对利什曼病的有前途的治疗策略方面发挥重要作用。
