Original Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Mar 28, 2012; 18(12): 1308-1318
Published online Mar 28, 2012. doi: 10.3748/wjg.v18.i12.1308
Probiotic modulation of dendritic cells co-cultured with intestinal epithelial cells
Ji Yeun Kim, Myeong Soo Park, Geun Eog Ji
Ji Yeun Kim, Geun Eog Ji, Department of Food and Nutrition, Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul 152-742, South Korea
Myeong Soo Park, Geun Eog Ji, Research Institute, Bifido Inc., Hongcheon, Gangwondo 250-804, South Korea
Author contributions: Kim JY performed most of the experiments; Park MS prepared and provided the probiotic bacteria and was involved in editing the manuscript; Kim JY and Ji GE designed the study and wrote the manuscript; Ji GE acted as a principle investigator.
Supported by The Small and Medium Business Administration, No. S1072365; and the Next-Generation BioGreen 21 Program, No. PJ008005, Rural Development Administration, South Korea
Correspondence to: Geun Eog Ji, PhD, Department of Food and Nutrition, Research Institute of Human Ecology, College of Human Ecology, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 152-742, South Korea. geji@snu.ac.kr
Telephone: +82-2-8808749 Fax: +82-2-8840305
Received: June 9, 2011
Revised: September 30, 2011
Accepted: January 22, 2012
Published online: March 28, 2012

AIM: To investigate cytokine production and cell surface phenotypes of dendritic cells (DC) in the presence of epithelial cells stimulated by probiotics.

METHODS: Mouse DC were cultured alone or together with mouse epithelial cell monolayers in normal or inverted systems and were stimulated with heat-killed probiotic bacteria, Bifidobacterium lactis AD011 (BL), Bifidobacterium bifidum BGN4 (BB), Lactobacillus casei IBS041 (LC), and Lactobacillus acidophilus AD031 (LA), for 12 h. Cytokine levels in the culture supernatants were determined by enzyme-linked immunosorbent assay and phenotypic analysis of DC was investigated by flow cytometry.

RESULTS: BB and LC in single-cultured DC increased the expression of I-Ad, CD86 and CD40 (I-Ad, 18.51 vs 30.88, 46.11; CD86, 62.74 vs 92.7, 104.12; CD40, 0.67 vs 6.39, 3.37, P < 0.05). All of the experimental probiotics increased the production of inflammatory cytokines, interleukin (IL)-6 and tumor necrosis factor (TNF)-α. However, in the normal co-culture systems, LC and LA decreased the expression of I-Ad (39.46 vs 30.32, 33.26, P < 0.05), and none of the experimental probiotics increased the levels of IL-6 or TNF-α. In the inverted co-culture systems, LC decreased the expression of CD40 (1.36 vs -2.27, P < 0.05), and all of the experimental probiotics decreased the levels of IL-6. In addition, BL increased the production of IL-10 (103.8 vs 166.0, P < 0.05) and LC and LA increased transforming growth factor-β secretion (235.9 vs 618.9, 607.6, P < 0.05).

CONCLUSION: These results suggest that specific probiotic strains exert differential immune modulation mediated by the interaction of dendritic cells and epithelial cells in the homeostasis of gastrointestinal tract.

Keywords: Dendritic cells, Intestinal epithelial cells, Probiotics, Co-culture, Immune modulation