Laboratory of Vector Biology, Department of Parasitology, Faculty of Science, Charles University, Prague, Czechia.
Laboratory of Structural Biochemistry of Immune Recognition, Department of Biochemistry, Faculty of Science, Charles University, Prague, Czechia.
Front Cell Infect Microbiol. 2020 Aug 24;10:427. doi: 10.3389/fcimb.2020.00427. eCollection 2020.
(Diptera: Phlebotominae) is a medically and veterinary important insect vector. It transmits the unicellular parasite that multiplies intracellularly in macrophages causing life-threatening visceral diseases. establishment in the vertebrate host is substantially influenced by immunomodulatory properties of vector saliva that are obligatorily co-injected into the feeding site. The repertoire of salivary molecules has already been revealed and, subsequently, several salivary proteins have been expressed. However, their immunogenic properties have never been studied. In our study, we tested three recombinant salivary proteins-an apyrase rSP01 and yellow-related proteins rSP03 and rSP03B-and showed their anti-inflammatory nature on the murine bone-marrow derived macrophages. Even in the presence of pro-inflammatory stimuli (IFN-γ and bacterial lipopolysaccharide, LPS), all three recombinant proteins inhibited nitric oxide production. Moreover, rSP03 seems to have a very strong anti-inflammatory effect since it enhanced arginase activity, increased the production of IL-10, and inhibited the production of TNF-α even in macrophages stimulated with IFN-γ and LPS. These results suggest that apyrase and yellow-related proteins may serve as enhancing factors in sand fly saliva, facilitating the development of infection along with their anti-haemostatic properties. Additionally, rSP03 and rSP03B did not elicit the delayed-type hypersensitivity response in mice pre-exposed to bites (measured as visible skin reaction). The results of our study may help to understand the potential function of recombinant's native counterparts and their role in transmission and establishment within the host.
（双翅目：Phlebotominae）是一种医学和兽医上重要的昆虫媒介。它传播单细胞寄生虫，这种寄生虫在巨噬细胞内繁殖，导致危及生命的内脏疾病。在脊椎动物宿主中的建立受到媒介唾液的免疫调节特性的极大影响，这些特性必须共同注入到进食部位。唾液分子的 repertoire 已经被揭示出来，随后，一些唾液蛋白已经被表达出来。然而，它们的免疫原性从未被研究过。在我们的研究中，我们测试了三种重组唾液蛋白-一种脱氨酶 rSP01 和黄色相关蛋白 rSP03 和 rSP03B-并显示它们对鼠骨髓来源的巨噬细胞具有抗炎作用。即使存在促炎刺激物（IFN-γ 和细菌脂多糖，LPS），所有三种重组蛋白都抑制了一氧化氮的产生。此外，rSP03 似乎具有非常强的抗炎作用，因为它增强了精氨酸酶的活性，增加了 IL-10 的产生，并抑制了 TNF-α的产生，即使在 IFN-γ 和 LPS 刺激的巨噬细胞中也是如此。这些结果表明，脱氨酶和黄色相关蛋白可能作为沙蝇唾液中的增强因子，在其抗凝血特性的同时促进 感染的发展。此外，rSP03 和 rSP03B 不会在预先暴露于 叮咬的小鼠中引起迟发型超敏反应（以可见的皮肤反应测量）。我们的研究结果可能有助于理解重组蛋白天然对应物的潜在功能及其在 传播和在宿主中建立的作用。
