Aguiar-Soares Rodrigo Dian de Oliveira, Roatt Bruno Mendes, Mathias Fernando Augusto Siqueira, Reis Levi Eduardo Soares, Cardoso Jamille Mirelle de Oliveira, Brito Rory Cristiane Fortes de, Ker Henrique Gama, Corrêa-Oliveira Rodrigo, Giunchetti Rodolfo Cordeiro, Reis Alexandre Barbosa
Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas/NUPEB, Universidade Federal de Ouro Preto, CEP 35400-000 Ouro Preto, Brazil.
Departamento de Análises Clínicas, Escola de Farmácia, Universidade Federal de Ouro Preto, CEP 35400-000 Ouro Preto, Brazil.
Vaccines (Basel). 2020 Nov 17;8(4):690. doi: 10.3390/vaccines8040690.
In this study, we performed a phase I and II clinical trial in dogs to evaluate the toxicity and immunogenicity of LBSap-vaccine prototype, in comparison to Leishmune and Leish-Tec vaccines. Twenty-eight dogs were classified in four groups: (i) control group received 1 mL of sterile 0.9% saline solution; (ii) LBSap group received 600 μg of promastigotes protein and 1 mg of saponin adjuvant; (iii) Leishmune; and (iv) Leish-Tec. The safety and toxicity of the vaccines were measured before and after three immunizations by clinical, biochemical, and hematological parameters. The clinical examinations revealed that some dogs of LBSap and Leishmune groups presented changes at the site of vaccination inoculum, such as nodules, mild edema, and local pain, which were transient and disappeared seventy-two hours after vaccination, but these results indicate that adverse changes caused by the immunizations are tolerable. The immunogenicity results demonstrate an increase of B lymphocytes CD21 regarding the Leishmune group and monocytes CD14 concerning LBSap and Leishmune groups. In the in vitro analyses, an increase in lymphoproliferative activity in LBSap and Leishmune groups was observed, with an increase of antigen-specific CD4 and CD8 T lymphocytes in the LBSap group. A second approach of in vitro assays aimed at evaluating the percentage of antigen-specific CD4 and CD8 T lymphocytes producers of IFN-γ and IL-4, where an increase in both IFN-γ producing subpopulations in the LBSap group was observed, also showed an increase in IFN-γ producers in CD8 lymphocytes in the Leish-Tec group. Our data regarding immunogenicity indicate that the vaccination process, especially with the LBSap vaccine, generated a protective immune response compatible with parasite control. Based on the foregoing, the LBSap vaccine would be suitable for further studies of phase III clinical trial in endemic areas with high prevalence and incidence of canine visceral leishmaniasis (VL) cases.
在本研究中，我们对犬进行了I期和II期临床试验，以评估LBSap疫苗原型与Leishmune和Leish-Tec疫苗相比的毒性和免疫原性。28只犬被分为四组：（i）对照组接受1 mL无菌0.9%生理盐水溶液；（ii）LBSap组接受600 μg前鞭毛体蛋白和1 mg皂苷佐剂；（iii）Leishmune组；（iv）Leish-Tec组。通过临床、生化和血液学参数在三次免疫前后测量疫苗的安全性和毒性。临床检查发现，LBSap组和Leishmune组的一些犬在接种疫苗部位出现变化，如结节、轻度水肿和局部疼痛，这些变化是短暂的，在接种疫苗72小时后消失，但这些结果表明免疫接种引起的不良变化是可以耐受的。免疫原性结果显示，与Leishmune组相比，LBSap组的B淋巴细胞CD21增加，与LBSap组和Leishmune组相比，单核细胞CD14增加。在体外分析中，观察到LBSap组和Leishmune组的淋巴细胞增殖活性增加，LBSap组中抗原特异性CD4和CD8 T淋巴细胞增加。体外试验的第二种方法旨在评估产生IFN-γ和IL-4的抗原特异性CD4和CD8 T淋巴细胞的百分比，其中观察到LBSap组中产生IFN-γ的两个亚群均增加，Leish-Tec组中CD8淋巴细胞产生IFN-γ的细胞也增加。我们关于免疫原性的数据表明，疫苗接种过程，尤其是使用LBSap疫苗，产生了与寄生虫控制相容的保护性免疫反应。基于上述情况，LBSap疫苗适合在犬内脏利什曼病（VL）病例高流行和高发病率的流行地区进一步进行III期临床试验研究。
