Effect of Lactobacillus GG and conditioned media on IL-1beta-induced IL-8 production in Caco-2 cells.
OBJECTIVE
To evaluate the anti-inflammatory effect of Lactobacillus casei rhamnosus GG (LGG) and its conditioned media (CM) in stimulated Caco-2 cells and to characterize the components of LGG that have the anti-inflammatory effect.


METHODS
Caco-2 cells were stimulated with IL-1beta with or without LGG or LGG-CM. Production of IL-8 was measured by enzyme-linked immunosorbent assay (ELISA). The transcriptional activities of the IL-8 gene and the NF-kappaB-responsive gene were evaluated by a transient transfection of the luciferase reporter gene. The effect on IkappaBalpha degradation was evaluated by Western blot analysis. To determine the nature of the immunomodulatory molecules, the LGG was modified to the following: treated with antibiotics, 4% formaldehyde, incubation at 95 degrees C, or sonication.


RESULTS
We demonstrated that the pretreatment of Caco-2 cells with LGG significantly inhibited IL-1beta-induced IL-8 production. Furthermore, LGG attenuated the IL-1beta-induced transcriptional activation of the IL-8 gene and the NF-kappaB-responsive gene, and attenuated the IL-1beta-induced IkappaBalpha degradation. Formaldehyde-fixed or antibiotics-treated LGG maintained the inhibitory effect, but heated LGG lost this effect. Sonicated LGG debris had a similar inhibitory effect with whole bacterial cells. LGG-CM attenuated IL-1beta-induced IL-8 production. This effect was maintained even when the conditioned media were heated.


CONCLUSIONS
LGG inhibited IL-1beta-induced IL-8 production in Caco-2 and this effect occurred at the transcriptional level, at least in part, by inhibition of the NF-kappaB signaling pathway. Both the structural material of LGG and the soluble factor secreted from LGG inhibited the IL-1beta-induced IL-8 production, and thus different substances may cause the effects.
Choi
Chang Hwan
CH
Department of Internal Medicine, Institute of Gastroenterology, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea.
Kim
Tae Il
TI
Lee
Sang Kil
SK
Yang
Kyung Min
KM
Kim
Won Ho
WH
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D015153:Blotting, Western; D018938:Caco-2 Cells; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000473:pathology; D017077:Culture Media, Conditioned; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology*; D016209:Interleukin-8 / Q000096:biosynthesis*; D007780:Lacticaseibacillus casei; D014407:Tumor Cells, Cultured
D017077:Culture Media, Conditioned; D053583:Interleukin-1beta; D016209:Interleukin-8