Intestinal Inflammatory Responses to the Indigenous Microbiota

Abstract

209 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2001.The potential for inflammatory cytokines to sensitize intestinal epithelial cells to indigenous bacteria was evaluated in HT-29 cells associated with Lactobacillus plantarum 299v in the presence or absence of tumor necrosis factor-alpha (TNF-alpha). Co-culture of TNF-alpha-stimulated HT-29 cells with L. plantarum 299v increased interleukin-8. (IL-8) mRNA expression above levels observed for cells treated with TNF-alpha alone. The ability of TNF-alpha-to upregulate CD14 and Toll-like receptor (TLR) expression and thereby enhance IL-8 mRNA expression in response to L. plantarum 299v was investigated. Baseline expression of CD14 mRNA and cell-surface CD14 was not altered by TNF-alpha. HT-29 cells did not express TLR2 mRNA. However TNF-alpha increased baseline HT-29 expression of TLR4 mRNA, and co-culture with L. plantarum 299v further enhanced TLR4 mRNA expression in TNF-alpha-treated HT-29 cells. These results indicate that neither CD 14 nor TLRs 2 and 4 are involved in the IL-8 mRNA response by HT-29 cells to L. plantarum 299v. However, these results indicate that intestinal epithelial cell responses to indigenous bacteria may contribute to intestinal inflammation.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD