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.
Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas/NUPEB, Departamento de Ciências Biológicas, Insituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil.
Parasitol Res. 2023 Dec;122(12):2917-2931. doi: 10.1007/s00436-023-07981-6. Epub 2023 Sep 28.
Tegumentary leishmaniasis (TL) is the main clinical manifestation of leishmaniasis, and it can cause the infected hosts to self-healing cutaneous lesions until mutilating scars in mucosal membranes, particularly in the nose and throat. The treatment against disease presents problems, and the diagnosis is hampered by variable sensitivity and/or specificity of the tests. In this context, the development of prophylactic vaccines could be considered as a strategy to control the disease. Previously, we showed that the recombinant LiHyp1 protein plus adjuvant protected mice from infection with Leishmania infantum, which causes visceral leishmaniasis. In the present study, we tested whether rLiHyp1 could induce protection against infection with L. amazonensis, a parasite species able to cause TL. We immunized BALB/c mice with rLiHyp1 plus saponin (rLiHyp1/S) or incorporated in micelles (rLiHyp1/M) as adjuvants and performed parasitological and immunological evaluations before and after infection. Results showed that after in vitro stimulation from spleen cell cultures using rLiHyp1 or a Leishmania antigenic extract (SLA), rLiHyp1/S and rLiHyp1/M groups developed a Th1-type immune response, which was characterized by high levels of IFN-γ, IL-2, TNF-α and IL-12 cytokines, nitrite, and IgG2a isotype antibodies when compared to values found in the control (saline, saponin, micelles alone) groups, which showed higher levels of anti-SLA IL-4, IL-10, and IgG1 antibodies before and after challenge. In addition, mice receiving rLiHyp1/S or rLiHyp1/M presented significant reductions in the lesion average diameter and parasite load in the infected tissue and internal organs. Blood samples were collected from healthy subjects and TL patients to obtain PBMC cultures, which were in vitro stimulated with rLiHyp1 or SLA, and results showed higher lymphoproliferation and IFN-γ production after stimulus using rLiHyp1, as compared to values found using SLA. These results suggest that rLiHyp1 plus adjuvant was protective against experimental TL and could also be considered for future studies as a vaccine candidate against human disease.
皮肤利什曼病（TL）是利什曼病的主要临床表现，可导致受感染的宿主自行治愈皮肤损伤，直至在粘膜上留下残缺的疤痕，特别是在鼻子和喉咙。针对该疾病的治疗存在问题，并且由于测试的敏感性和/或特异性存在差异，诊断也受到阻碍。在这种情况下，可以考虑开发预防性疫苗作为控制疾病的策略。以前，我们已经证明重组 LiHyp1 蛋白加佐剂可保护感染内脏利什曼病的小鼠免受感染。在本研究中，我们测试了 rLiHyp1 是否可以诱导对感染引起 TL 的美洲利什曼原虫的保护。我们用 rLiHyp1 加皂素（rLiHyp1/S）或包埋在胶束中（rLiHyp1/M）作为佐剂免疫 BALB/c 小鼠，并在感染前后进行寄生虫学和免疫学评估。结果表明，在用 rLiHyp1 或利什曼抗原提取物（SLA）刺激脾细胞培养物后，rLiHyp1/S 和 rLiHyp1/M 组产生了 Th1 型免疫反应，其特征是 IFN-γ、IL-2、TNF-α 和 IL-12 细胞因子水平较高，与对照组（生理盐水、皂素、单独胶束）相比，rLiHyp1/S 和 rLiHyp1/M 组的亚硝酸盐和 IgG2a 同种型抗体水平较高，而对照组在攻毒前后的 IL-4、IL-10 和 IgG1 抗体水平较高。此外，接受 rLiHyp1/S 或 rLiHyp1/M 治疗的小鼠在感染组织和内脏器官中的病变平均直径和寄生虫载量均显著降低。从健康受试者和 TL 患者采集血液样本以获得 PBMC 培养物，并用 rLiHyp1 或 SLA 体外刺激培养物，结果表明 rLiHyp1 刺激后淋巴细胞增殖和 IFN-γ 产生更高，与 SLA 相比。这些结果表明，rLiHyp1 加佐剂对实验性 TL 具有保护作用，也可考虑作为针对人类疾病的候选疫苗进行进一步研究。
