Dias Daniel S, Martins Vívian T, Ribeiro Patrícia A F, Ramos Fernanda F, Lage Daniela P, Tavares Grasiele S V, Mendonça Débora V C, Chávez-Fumagalli Miguel A, Oliveira Jamil S, Silva Eduardo S, Gomes Dawidson A, Rodrigues Michele A, Duarte Mariana C, Galdino Alexsandro S, Menezes-Souza Daniel, Coelho Eduardo A F
Programa de Pós-Graduação em Ciências da Saúde: Infectologia e Medicina Tropical, Faculdade de Medicina,Universidade Federal de Minas Gerais,Belo Horizonte, Minas Gerais,Brazil.
Departamento de Bioquímica e Imunologia,Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais,Belo Horizonte, Minas Gerais,Brazil.
Parasitology. 2018 May;145(6):740-751. doi: 10.1017/S0031182017001731. Epub 2017 Nov 8.
In this study, a Leishmania hypothetical protein, LiHyS, was evaluated regarding its antigenicity, immunogenicity and protective efficacy against visceral leishmaniasis (VL). Regarding antigenicity, immunoblottings and an enzyme-linked immunosorbent assay using human and canine sera showed high sensitivity and specificity values for the recombinant protein (rLiHyS) in the diagnosis of VL. When evaluating the immunogenicity of LiHyS, which is possibly located in the parasite's flagellar pocket, proliferative assays using peripheral blood mononuclear cells from healthy subjects or VL patients showed a high proliferative index in both individuals, when compared to the results obtained using rA2 or unstimulated cultures. Later, rLiHyS/saponin was inoculated in BALB/c mice, which were then challenged with Leishmania infantum promastigotes. The vaccine induced an interferon-γ, interleukin (IL)-12 and granulocyte-macrophage colony-stimulating factor production, which was maintained after infection and which was associated with high nitrite and IgG2a antibody levels, as well as low IL-4 and IL-10 production. Significant reductions in the parasite load in liver, spleen, bone marrow and draining lymph nodes were found in these animals. In this context, the present study shows that the rLiHyS has the capacity to be evaluated as a diagnostic marker or vaccine candidate against VL.
在本研究中，对利什曼原虫的一种假定蛋白LiHyS进行了评估，考察其针对内脏利什曼病（VL）的抗原性、免疫原性和保护效力。关于抗原性，使用人和犬血清进行的免疫印迹和酶联免疫吸附测定显示，重组蛋白（rLiHyS）在VL诊断中具有较高的敏感性和特异性值。在评估可能位于寄生虫鞭毛袋中的LiHyS的免疫原性时，与使用rA2或未刺激培养物获得的结果相比，使用健康受试者或VL患者的外周血单核细胞进行的增殖测定显示，这两类个体的增殖指数均较高。随后，将rLiHyS/皂苷接种到BALB/c小鼠中，然后用婴儿利什曼原虫前鞭毛体对其进行攻击。该疫苗诱导了干扰素-γ、白细胞介素（IL）-12和粒细胞-巨噬细胞集落刺激因子的产生，感染后这些因子仍持续存在，且与高亚硝酸盐和IgG2a抗体水平以及低IL-4和IL-10产生相关。在这些动物中发现肝脏、脾脏、骨髓和引流淋巴结中的寄生虫负荷显著降低。在此背景下，本研究表明rLiHyS有能力作为VL的诊断标志物或疫苗候选物进行评估。
