Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Front Immunol. 2020 Oct 23;11:1725. doi: 10.3389/fimmu.2020.01725. eCollection 2020.
The live non-pathogenic Leishmania tarantolae has recently provided a promising approach as an effective vaccine candidate against experimental leishmaniasis (ILL). Here, we evaluated the immunoprotective potential of the live Iranian Lizard Leishmania mixed with CpG adjuvant against infection in BALB/c mice. Four groups of female BALB/c mice were included in the study. The first and second groups received PBS and CpG, respectively. The immunized groups received 2 × 10 ILL promastigotes and the CpG-mixed ILL (ILL+CpG). Injections were performed subcutaneously in the right footpad. Three weeks later, all mice were challenged with 2 × 10 metacyclic promastigotes of ; inoculation was done in the left footpad. The measurement of footpad swelling and fluorescent imaging were used to evaluate disease progress during infection course. Eight weeks after challenge, all mice were sacrificed and the cytokines levels (IFN-γ, IL-4, and IL-10) and sera antibodies concentrations (IgG2a and IgG1) using ELISA assay, nitric oxide production using Griess assay, and arginase activity in cultured splenocytes, were measured. In addition, direct fluorescent microscopy analysis and qPCR assay were used to quantify the splenic parasite burden. The results showed that mice immunized with ILL+CpG were protected against the development of the dermal lesion. Moreover, they showed a significant reduction in the parasite load, in comparison to the control groups. The observed protection was associated with higher production of IFN-γ, as well as a reduction in IL-4 level. Additionally, the results demonstrated that arginase activity was decreased in ILL+CpG group compared to other groups. Immunization using ILL+CpG induces a protective immunity; indicating that ILL with an appropriate adjuvant would be a suitable choice for vaccination against leishmaniasis.
活的非致病性利什曼原虫 tarantolae 最近提供了一种有希望的方法，作为一种有效的实验性利什曼病（ILL）疫苗候选物。在这里，我们评估了活的伊朗蜥蜴利什曼原虫与 CpG 佐剂混合后对 BALB/c 小鼠感染的免疫保护潜力。 该研究包括四组雌性 BALB/c 小鼠。第一组和第二组分别接受 PBS 和 CpG。免疫组接受 2×10 ILL 前鞭毛体和 CpG 混合的 ILL（ILL+CpG）。皮下注射到右足底。3 周后，所有小鼠均用 2×10 个循环前鞭毛体接种 ；接种于左足底。通过测量足垫肿胀和荧光成像来评估感染过程中的疾病进展。挑战后 8 周，所有小鼠均被处死，并通过 ELISA 测定细胞因子水平（IFN-γ、IL-4 和 IL-10）和血清抗体浓度（IgG2a 和 IgG1）、Griess 测定法测定一氧化氮产生量以及培养的脾细胞中的精氨酸酶活性。此外，还使用直接荧光显微镜分析和 qPCR 测定来定量脾脏寄生虫负荷。 结果表明，用 ILL+CpG 免疫的小鼠可防止皮肤病变的发展。此外，与对照组相比，它们显示寄生虫负荷显著降低。观察到的保护与 IFN-γ的产生增加以及 IL-4 水平的降低有关。此外，结果表明，与其他组相比，ILL+CpG 组的精氨酸酶活性降低。 用 ILL+CpG 免疫诱导保护性免疫；表明用适当的佐剂免疫利什曼原虫将是预防利什曼病的一种合适选择。
