Department of Microbiology and Biotechnology, Max Rubner-Institut, Hermann-Weigmann-Str. 1, D-24103 Kiel, Germany.
Department of Physiology and Biochemistry of Nutrition, Max Rubner-Institut, Hermann-Weigmann-Str. 1, D-24103 Kiel, Germany.
Immunobiology. 2014 Mar;219(3):208-17. doi: 10.1016/j.imbio.2013.10.005. Epub 2013 Oct 14.
We characterized the immunomodulating potential of a number of lactobacilli isolated from an African fermented food by co-incubation with peripheral blood mononuclear cells (PBMCs). Two strains with different immune modulating properties were genetically compared by suppression subtractive hybridization (SSH).
From 48 Lactobacillus strains isolated from Kimere, African fermented pearl millet dough, 10 were selected based on their bile salt tolerance. Their effects on secretion by PBMCs of the T-helper cells Th1- and Th2-cytokines IFN-γ and IL-4, respectively, in the presence or absence of staphylococcal enterotoxin A (SEA) were assessed. To study the genetic basis of different immune-modulating properties, a subtracted cDNA library for L. fermentum strains K1-Lb1 (Th1 inducer) and K8-Lb1 (Th1 and Th2 suppressor) was constructed using SSH. Finally, adhesion of these strains to hydrocarbons (relative hydrophobicity) and to human HT-29 colonic epithelial cell line was assessed.
Two strains, K1-Lb1 and K4-Lb6, induced basal IFN-γ secretion. Four strains, K1-Lb6, K6-Lb2, K7-Lb1, and K8-Lb1 diminished INF-γ secretion by SEA-stimulated PBMCs. All strains, except K1-Lb1, K2-Lb4, and K9-Lb3, inhibited SEA-stimulated IL-4 secretion. Comparing the genomes of K1-Lb1 and K8-Lb1 by SSH indicated that K1-Lb1 is able to synthetize polysaccharides, for the synthesis of which K1-Lb8 appears to lack enzymes. A difference in the hydrophobicity properties of the surfaces of both strains indicated that this has impact on their surface.
The K1-Lb1-specific sequences encoding putative glycosyltransferases and enzymes for polysaccharides synthesis may account for the observed differences in immunomodulation and surface properties between the two strains and for mediating potential probiotic effects.
我们通过与外周血单个核细胞（PBMCs）共孵育，研究了从非洲发酵食品中分离出的多种乳酸菌的免疫调节潜力。通过抑制性消减杂交（SSH），对具有不同免疫调节特性的两种菌株进行了基因比较。
从 48 株从非洲发酵珍珠 millet 面团中分离出的 Lactobacillus 菌株中，根据其胆汁盐耐受性选择了 10 株。在存在或不存在葡萄球菌肠毒素 A（SEA）的情况下，评估它们对 PBMCs 分泌 Th1 和 Th2 细胞因子 IFN-γ 和 IL-4 的影响。为了研究不同免疫调节特性的遗传基础，使用 SSH 构建了 L. fermentum 菌株 K1-Lb1（Th1 诱导剂）和 K8-Lb1（Th1 和 Th2 抑制剂）的消减 cDNA 文库。最后，评估了这些菌株对碳氢化合物（相对疏水性）和人 HT-29 结肠上皮细胞系的粘附性。
两种菌株 K1-Lb1 和 K4-Lb6 诱导基础 IFN-γ 分泌。四种菌株 K1-Lb6、K6-Lb2、K7-Lb1 和 K8-Lb1 减少了 SEA 刺激的 PBMCs 中 IFN-γ 的分泌。除了 K1-Lb1、K2-Lb4 和 K9-Lb3 之外，所有菌株都抑制了 SEA 刺激的 IL-4 分泌。通过 SSH 比较 K1-Lb1 和 K8-Lb1 的基因组表明，K1-Lb1 能够合成多糖，而 K8-Lb1 似乎缺乏合成多糖的酶。两种菌株表面疏水性特性的差异表明，这会影响它们的表面。
K1-Lb1 特异性序列编码假定的糖基转移酶和多糖合成酶，可能解释了这两种菌株在免疫调节和表面特性方面的差异，以及介导潜在的益生菌作用。
