Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil.
Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil; Grupo Informática de Biossistemas e Genômica, Instituto René Rachou, Fiocruz Minas, Belo Horizonte, Minas Gerais, Brazil.
Cell Immunol. 2022 Oct;380:104592. doi: 10.1016/j.cellimm.2022.104592. Epub 2022 Sep 5.
The development of an immunogenic, effective, and safe vaccine is essential as an alternative for disease control. The present study aimed to evaluate the immunogenicity and efficacy potential of a polyepitope T-cell antigen candidate against visceral leishmaniasis in a murine model. BALB/c mice were immunized with three doses subcutaneously with Poly-T Leish alone or adjuvanted with Saponin plus Monophosphoryl lipid A, with 15-day intervals between doses, and challenged with 10 stationary-phase Leishmania infantum promastigotes via tail vein. Immunogenicity and parasitism in spleen and liver of immunized mice were evaluated 45 days post-challenge. Our results revealed that the immunization with Poly-T Leish and Poly-T Leish/SM increases the percentage of specific T (CD4 and CD8) lymphocytes proliferation in vitro after antigen-specific stimulation. Also, Poly-T Leish and Poly-T Leish/SM groups showed a high percentage of IFN-γ and TNF-α-producing T cells, meanwhile, the Poly-T Leish/SM group also showed an increased percentage of multifunctional T cells producing double and triple-positive (IFN-γTNF-αIL-2) cytokines. The immunization with Poly-T Leish or Poly-T Leish/SM stimulated a decreased IL-4 and IL-10 compared to the Saline and adjuvant group. Poly-T Leish/SM immunized mice exhibit a noteworthy reduction in the parasite burden (spleen and liver) through real-time PCR (96%). Moreover, we observed higher nitrite secretion in 120-hour stimulated-culture supernatant using Griess method. We demonstrated that the Poly-T Leish/SM candidate was potentially immunogenic, providing enhancement of protective immune mechanisms, and conferred protection reducing parasitism. Our candidate was considered potential against visceral leishmaniasis, and eventually, could be tested in phase I and II clinical trials in dogs.
开发一种具有免疫原性、有效性和安全性的疫苗作为疾病控制的替代方法至关重要。本研究旨在评估一种多表位 T 细胞抗原候选物在小鼠模型中针对内脏利什曼病的免疫原性和功效潜力。BALB/c 小鼠通过皮下免疫三种剂量的 Poly-T Leish，单独或与 Saponin 加单磷酰脂质 A 佐剂一起免疫，剂量间隔为 15 天，通过尾静脉用 10 个静止期利什曼原虫前鞭毛体进行攻毒。攻毒后 45 天评估免疫小鼠脾脏和肝脏中的免疫原性和寄生虫。我们的结果表明，Poly-T Leish 和 Poly-T Leish/SM 免疫可增加抗原特异性刺激后体外特异性 T（CD4 和 CD8）淋巴细胞增殖的百分比。此外，Poly-T Leish 和 Poly-T Leish/SM 组显示出高比例的 IFN-γ 和 TNF-α产生的 T 细胞，同时，Poly-T Leish/SM 组还显示出产生双阳性和三阳性（IFN-γTNF-αIL-2）细胞因子的多功能 T 细胞的比例增加。与盐水和佐剂组相比，Poly-T Leish 或 Poly-T Leish/SM 免疫可刺激降低 IL-4 和 IL-10 的产生。Poly-T Leish/SM 免疫的小鼠通过实时 PCR（96%）显示寄生虫负荷（脾脏和肝脏）显著降低。此外，我们使用 Griess 法观察到在 120 小时刺激培养物上清液中更高的亚硝酸盐分泌。我们证明 Poly-T Leish/SM 候选物具有潜在的免疫原性，增强了保护性免疫机制，并提供了减少寄生虫的保护作用。我们的候选物被认为对内脏利什曼病具有潜在的作用，最终可以在狗的 I 期和 II 期临床试验中进行测试。
