Avian coccidiosis leads to severe economic losses on the global poultry industry. Immune mapped protein-1 (IMP1) is a novel membrane protein, and was reported to be a candidate protective antigen. However, production and utilization modes of IMP1 using Lactococcus lactis as delivery vector were not reported untill now. In the present study, Eimeria tenella IMP1 (EtIMP1) protein was expressed in L. lactis under the nisin-inducible promoter, and EtIMP1 protein was produced in cytoplasmic, cell wall-anchored and secreted forms. Each chicken was orally immunized with one of the three live EtIMP1-expressing lactococci three times at 2 weeks intervals (immunized group), or with live bacteria harboring empty vector (immunized control group). Chickens in immunized and immunized control group were challenged with E. tenella sporulated oocysts to assess the immune responses. The results showed that proliferative responses of peripheral blood T lymphocytes, mRNA expression levels of IL-2, IL-4, IL-10 and IFN-γ in spleen tissues, levels of serum IgG and secretory IgA (sIgA) in cecal lavage fluids from chickens in immunized group were all significantly elevated compared to that in immunized control group. All three the live EtIMP1-expressing lactococci significantly decreased oocyst shedding, alleviated pathological damage in cecum and improved weight gain compared with bacteria harboring empty vector. These results suggested EtIMP1 protein delivered by L. lactis might be a promising candidate in developing novel vaccines against Eimeria infection.

禽球虫病给全球家禽业造成严重的经济损失。免疫映射蛋白-1 (IMP1) 是一种新型膜蛋白，据报道是候选保护性抗原。然而，以乳酸乳球菌为递送载体的IMP1的生产和利用方式目前尚未见报道。在本研究中，柔嫩艾美耳球虫 IMP1 (EtIMP1) 蛋白在乳酸链球菌中在乳链菌肽诱导型启动子的作用下表达，并且 EtIMP1 蛋白以细胞质、细胞壁锚定和分泌的形式产生。每只鸡分别用三种表达 EtIMP1 的活乳球菌中的一种口服免疫 3 次，间隔 2 周（免疫组），或用带有空载体的活细菌（免疫对照组）进行口服免疫。用柔嫩球虫孢子卵囊攻击免疫组和免疫对照组的鸡以评估免疫反应。结果显示,外周血T淋巴细胞增殖反应,脾组织中IL-2、IL-4、IL-10、IFN-γ mRNA表达水平,盲肠灌洗液中血清IgG和分泌性IgA(sIgA)水平。免疫组鸡均较免疫对照组显着升高。与携带空载体的细菌相比，这三种表达 EtIMP1 的活乳球菌均显着减少了卵囊脱落，减轻了盲肠的病理损伤，并改善了体重增加。这些结果表明，乳酸乳球菌传递的 EtIMP1 蛋白可能是开发针对艾美耳球虫感染的新型疫苗的有希望的候选者。