title: Lactoferrin downregulates pro-inflammatory cytokines upexpressed in intestinal epithelial cells infected with invasive or noninvasive Escherichia coli strains.
abstract: Intestinal epithelial cells are able to differentially interact with commensal or pathogenic microorganisms, triggering a physiological or destructive inflammation, respectively. To mimic commensal-enteroinvasive bacteria-host cell interaction, we infected Caco-2 cells with noninvasive Escherichia coli HB101 and with recombinant invasive E. coli HB101(pRI203). Using DNA microarray mRNA profiling and ELISA assays, we studied the expression of several cytokine and cytokine-related genes in infected Caco-2 cells in the absence or presence of bovine lactoferrin (bLf). Infection of Caco-2 cells with the noninvasive strain induced a slight increase in the expression of interleukin 8 (IL-8), whereas infection with invasive E. coli HB101(pRI203) induced a significant increase in the expression of IL-8 as well as other pro-inflammatory cytokines. The addition of bLf, in native- or holo-form, did not influence expression of cytokine genes by uninfected Caco-2 cells, but it decreased expression of IL-8 by cells infected with E.coli HB101. Moreover, except for IL-8, bLfs dramatically downregulated pro-inflammatory cytokines upexpressed by Caco-2 cells infected with the invasive strain. Although IL-8 was decreased by bLfs, it remained upregulated, suggesting that it could be a signal of persistence of intracellular bacteria. The bLf ability to reduce expression of some pro-inflammatory cytokines, which appears independent of its iron saturation, might represent an important natural mechanism in regulating epithelial cell responses to pathogenic bacteria and in limiting cell damage and the spread of infections.
authors.affiliation: Department of Public Health Sciences, University of Rome La Sapienza, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Berlutti
authors.forename: Serena
authors.initials: S
authors.lastname: Schippa
authors.forename: Clara
authors.initials: C
authors.lastname: Morea
authors.forename: Serena
authors.initials: S
authors.lastname: Sarli
authors.forename: Brunella
authors.initials: B
authors.lastname: Perfetto
authors.forename: Giovanna
authors.initials: G
authors.lastname: Donnarumma
authors.forename: Piera
authors.initials: P
authors.lastname: Valenti
mesh_terms: D000818:Animals; D018938:Caco-2 Cells; D002417:Cattle; D016207:Cytokines / Q000276:immunology / Q000378:metabolism*; D015536:Down-Regulation / Q000187:drug effects*; D004847:Epithelial Cells / Q000187:drug effects* / Q000382:microbiology*; D004926:Escherichia coli / Q000145:classification / Q000472:pathogenicity / Q000502:physiology*; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D007422:Intestines / Q000166:cytology*; D007781:Lactoferrin / Q000494:pharmacology*; D013347:Subcellular Fractions; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D016207:Cytokines; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D007781:Lactoferrin