immunomodulatory effects of adipose-derived mesenchymal stem cells on epithelial cells function in response to vibrio cholera in a co-culture model

Inflammation-induced by the interaction of the vibrio cholerae with the epithelial cells is considered as a main cause of bacteria spreading through the gastrointestinal tract and its consequences. because of the immunomodulatory and antibacterial properties of adipose-derived mesenchymal stem cells (ad-mscs), this study aimed to investigate the effect of ad-mscs on the interaction of the bacterial-epithelial cell. caco-2 differentiated to intestinal epithelial cells co-cultured with ad-mscs in a 1:1 ratio of the surface area of six-well plates, for 48 hours. after exposure to vibrio cholerae, bacterial attachment and internalization were evaluated. secretions of interleukin (il) -6, prostaglandin e2 (pge2), and nitric oxide (no) were also measured using elisa, and griess assay, respectively. in addition, the expression of chloratoxin (ctx-β) and inflammatory cytokines such as tnf-α, il-1β, and il-8 were evaluated by real-time polymerase chain reaction (rt-pcr). the rate of apoptosis was also evaluated by annexin v-pi flow cytometry. bacterial attachment and ctx-β expression were significantly reduced in the co-culture group compared to the vibrio cholerae-exposed caco-2. il-6 and pge2 secretion increased in the coculture group. no, was also slightly reduced in exposure to vibrio cholerae. an elevated level of bacterial internalization was observed in the co-culture group compared to the caco-2 cells leading to an increase in the expression of pro-inflammatory cytokines. the rate of apoptosis was also increased significantly. cell-to-cell contact of ad-mscs and caco-2 promoted inflammatory responses and disruption of the epithelium barrier by enhancing bacterial invasion. this may be due to the high expression of surface matrix metalloproteinases on mscs.