ABSTRACT In the present study, recombinant L. lactis NZ9000 displaying anchored dendritic cell-targeting peptide (DCpep) and E. tenella 3-1E protein was constructed. Chickens were orally immunized with the recombinant lactococci for three times at 2-week intervals. After three immunizations, chickens were challenged with E. tenella sporulated oocyst, and the immune response and protective efficacy were evaluated. The finding from animal experiments showed recombinant lactococci expressing anchored DCpep-3-1E protein elicited higher levels of 3-1E specific serum IgG and secretory IgA (sIgA) in caecal lavage, higher proportions of CD4+ and CD8α+ cells in peripheral blood, and higher mRNA expression levels of IL-2 and IFN-γ in the spleen compared to 3-1E-expressing lactococci, and hence offered obvious protective efficacy against homologous challenge. The present work demonstrated that cell surface-displayed target protein and immune enhancers in lactococci may be a promising approach to enhance immunity and immune efficacy against pathogen infection.

中文翻译：

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重组乳酸乳球菌共表达树突状细胞靶肽和 E.tenella 3-1E 蛋白：对同源攻击的免疫反应和功效

摘要 在本研究中，构建了展示锚定树突状细胞靶向肽 (DCpep) 和 E.tenella 3-1E 蛋白的重组乳酸乳球菌 NZ9000。用重组乳球菌以2周的间隔对鸡进行3次口服免疫。3 次免疫后，用球虫孢子化卵囊攻击鸡，并评估免疫反应和保护功效。动物实验结果表明，表达锚定 DCpep-3-1E 蛋白的重组乳球菌在盲肠灌洗液中引发了更高水平的 3-1E 特异性血清 IgG 和分泌性 IgA（sIgA），外周血中 CD4+ 和 CD8α+ 细胞的比例更高，并且与表达 3-1E 的乳球菌相比，脾脏中 IL-2 和 IFN-γ 的 mRNA 表达水平，因此对同源攻击具有明显的保护功效。