Goblet Cell Derived RELM-β Recruits CD4+ T Cells during Infectious Colitis to Promote Protective Intestinal Epithelial Cell Proliferation.

Enterohemorrhagic Escherichia coli and related food and waterborne pathogens pose significant threats to human health. These attaching/effacing microbes infect the apical surface of intestinal epithelial cells (IEC), causing severe diarrheal disease. Colonizing the intestinal luminal surface helps segregate these microbes from most host inflammatory responses.

The Serine Protease Autotransporter Pic Modulates Citrobacter rodentium Pathogenesis and Its Innate Recognition by the Host.

Bacterial pathogens produce a number of autotransporters that possess diverse functions. These include the family of serine protease autotransporters of Enterobacteriaceae (SPATEs) produced by enteric pathogens such as Shigella flexneri and enteroaggregative Escherichia coli. Of these SPATEs, one termed "protein involved in colonization," or Pic, has been shown to possess mucinase activity in vitro, but to date, its role in in vivo enteric pathogenesis is unknown.

The mucin Muc2 limits pathogen burdens and epithelial barrier dysfunction during Salmonella enterica serovar Typhimurium colitis.

Salmonella enterica serovar Typhimurium is a model organism used to explore the virulence strategies underlying Salmonella pathogenesis. Although intestinal mucus is the first line of defense in the intestine, its role in protection against Salmonella is still unclear. The intestinal mucus layer is composed primarily of the Muc2 mucin, a heavily O-glycosylated glycoprotein.

Identification of superoxide production by Arabidopsis thaliana aldehyde oxidases AAO1 and AAO3.

Plant aldehyde oxidases (AOs) have gained great attention during the last years as they catalyze the last step in the biosynthesis of the phytohormone abscisic acid by oxidation of abscisic aldehyde. Furthermore, oxidation of indole-3-acetaldehyde by AOs is likely to represent one route to produce another phytohormone, indole-3-acetic acid, and thus, AOs play important roles in many aspects of plant growth and development. In the present work we demonstrate that heterologously expressed AAO1 and AAO3, two prominent members of the AO family from Arabidopsis thaliana, do not only generate hydrogen peroxide but also superoxide anions by transferring aldehyde-derived electrons to molecular oxygen.

MyD88 signaling promotes both mucosal homeostatic and fibrotic responses during Salmonella-induced colitis.

Salmonella enterica serovar Typhimurium is a clinically important gram-negative, enteric bacterial pathogen that activates several Toll-like receptors (TLRs). While TLR signaling through the adaptor protein MyD88 has been shown to promote inflammation and host defense against the systemic spread of S. Typhimurium, curiously, its role in the host response against S.

Innate host responses to enteric bacterial pathogens: a balancing act between resistance and tolerance.

Infection by enteric bacterial pathogens activates pathogen recognition receptors, leading to innate responses that promote host defence. While responses that promote host 'resistance' to infection, through the release of antimicrobial mediators, or the recruitment of inflammatory cells aimed at clearing the infection are best known, recent studies have begun to identify additional innate driven responses that instead promote intestinal tissue repair and host survival. Described as infection 'tolerance' responses, we and others have primarily studied these responses in the Citrobacter rodentium infection model.

Xanthine dehydrogenase AtXDH1 from Arabidopsis thaliana is a potent producer of superoxide anions via its NADH oxidase activity.

Xanthine dehydrogenase AtXDH1 from Arabidopsis thaliana is a key enzyme in purine degradation where it oxidizes hypoxanthine to xanthine and xanthine to uric acid. Electrons released from these substrates are either transferred to NAD(+) or to molecular oxygen, thereby yielding NADH or superoxide, respectively. By an alternative activity, AtXDH1 is capable of oxidizing NADH with concomitant formation of NAD(+) and superoxide.

Identification of a novel E3 ubiquitin ligase that is required for suppression of premature senescence in Arabidopsis.

During leaf senescence, resources are recycled by redistribution to younger leaves and reproductive organs. Candidate pathways for the regulation of onset and progression of leaf senescence include ubiquitin-dependent turnover of key proteins. Here, we identified a novel plant U-box E3 ubiquitin ligase that prevents premature senescence in Arabidopsis plants, and named it SENESCENCE-ASSOCIATED E3 UBIQUITIN LIGASE 1 (SAUL1).

Binding of sulfurated molybdenum cofactor to the C-terminal domain of ABA3 from Arabidopsis thaliana provides insight into the mechanism of molybdenum cofactor sulfuration.

The molybdenum cofactor sulfurase ABA3 from Arabidopsis thaliana is needed for post-translational activation of aldehyde oxidase and xanthine dehydrogenase by transferring a sulfur atom to the desulfo-molybdenum cofactor of these enzymes. ABA3 is a two-domain protein consisting of an NH(2)-terminal NifS-like cysteine desulfurase domain and a C-terminal domain of yet undescribed function. The NH(2)-terminal domain of ABA3 decomposes l-cysteine to yield elemental sulfur, which subsequently is bound as persulfide to a conserved protein cysteinyl residue within this domain.