Department of Microbiology and Clinical Immunology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland.
Department of Internal Diseases with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland.
J Anim Physiol Anim Nutr (Berl). 2019 May;103(3):882-893. doi: 10.1111/jpn.13085. Epub 2019 Mar 27.
Nisin, a lantibiotic bacteriocin, has been used for years as a natural food preservative. In addition to its antimicrobial activity, nisin also shows immunomodulatory properties, and the nisin-producing Lactococcus lactis strain has been successfully tested as a probiotic in weaned piglets. However, the impact of nisin on porcine immune cells has not yet been explored. The objective of the present study was to examine the in vitro immunomodulatory effect of nisin on porcine peripheral blood leucocytes. The whole heparinized blood samples or freshly isolated peripheral blood mononuclear cells (PBMCs) were incubated with different nisin concentrations (0, 1.56, 3.125, 6.25, 12.5, 25 or 50 µg/ml) for 1, 24, 48 or 72 hr. Escherichia coli bacteria were used to stimulate blood phagocytes, while concanavalin A and lipopolysaccharide from E. coli were used as mitogens. Control cells remained unstimulated. MTT colorimetric assay was used to evaluate PBMCs viability and mitogenic response. Phagocyte activity and T-cell proliferation were measured by flow cytometry. Flow cytometer was also used for immunophenotyping of T cells. Cytokine levels in the culture media were determined using commercial immunoassay (ELISA) kits. The highest concentration of nisin exhibited proliferative activity (p ˂ 0.05), stimulated interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) production (both at p ˂ 0.001), and increased the percentage of CD4 CD8 T cells (p ˂ 0.001) among unstimulated leucocytes. After cell stimulation, however, the highest nisin concentration showed antiproliferative activity (p ˂ 0.05), decreased phagocytic functions (p ˂ 0.05) and inhibited the synthesis of IL-6 (time- and concentration-dependent effect). As a typical bacterial product, nisin had a stronger impact on innate immune cells, and its effect on T cells was likely a consequence of the modulation of the activity of antigen-presenting cells. Nisin may be a good candidate as an immunomodulator in pig breeding.
乳链菌肽（Nisin）作为一种天然的食品防腐剂，已经使用了很多年。除了具有抗菌活性外，乳链菌肽还具有免疫调节特性，并且产乳链菌肽的乳酸乳球菌菌株已成功作为断奶仔猪的益生菌进行了测试。然而，乳链菌肽对猪免疫细胞的影响尚未得到探索。本研究的目的是研究乳链菌肽对猪外周血白细胞的体外免疫调节作用。将整个肝素化的全血样本或新鲜分离的外周血单核细胞（PBMCs）与不同浓度的乳链菌肽（0、1.56、3.125、6.25、12.5、25 或 50 µg/ml）孵育 1、24、48 或 72 小时。使用大肠杆菌细菌刺激血液吞噬细胞，而刀豆蛋白 A 和大肠杆菌脂多糖则用作有丝分裂原。对照细胞保持未刺激状态。MTT 比色法用于评估 PBMCs 的活力和有丝分裂反应。通过流式细胞术测量吞噬细胞活性和 T 细胞增殖。流式细胞仪还用于 T 细胞的免疫表型分析。使用商业免疫测定（ELISA）试剂盒测定培养基中的细胞因子水平。最高浓度的乳链菌肽表现出增殖活性（p < 0.05），刺激白细胞介素-1β（IL-1β）和白细胞介素-6（IL-6）的产生（均 p < 0.001），并增加 CD4+CD8+T 细胞的百分比（p < 0.001）。然而，在细胞刺激后，最高浓度的乳链菌肽显示出抗增殖活性（p < 0.05），降低吞噬功能（p < 0.05）并抑制 IL-6 的合成（时间和浓度依赖性效应）。作为一种典型的细菌产物，乳链菌肽对固有免疫细胞的影响更强，其对 T 细胞的影响可能是抗原呈递细胞活性调节的结果。乳链菌肽可能是猪养殖中免疫调节剂的良好候选物。
