The expression of COX2 protein induced by Lactobacillus rhamnosus GG, endotoxin and lipoteichoic acid in T84 epithelial cells

Lactobacillus rhamnosus GG (L. rhamnosus GG) possess immunomodulatory effects in the host. In the present study, the effect of L. rhamnosus GG on cyclooxygenase 2 (COX2) expression and its pharmacological control was investigated in human T84 colon epithelial cells.T84 cells were exposed to freeze-dried L. rhamnosus GG in vitro, and the expression of COX2 was detected by Western blot.L. rhamnosus GG induced COX2 expression in a time- and concentration-dependent manner in T84 cells. COX2 expression was inhibited by tyrosine kinase inhibitor genistein (100 micromol l(-1)), p38 mitogen-activated protein kinase (MAP kinase) inhibitor (SB203580; 1 micromol l(-1)) and dexamethasone (10 micromol l(-1)), whereas inhibitors of p42/44 MAP kinase (PD98095; 10 micromol l(-1)), protein kinase C (Ro 31-8220; 1 micromol l(-1)) and transcription factor nuclear factor kappa B (NF-kappaB) [pyrrolidinedithiocarbamate (PDTC) 100 micromol l(-1)] had practically no effect.The results provide novel information on the cellular mechanisms involved in the interaction between L. rhamnosus GG and colon epithelial cells.