Early subclinical stages of the inflammatory bowel diseases: insights from human and animal studies.

The inflammatory bowel diseases (IBD) occur in genetically susceptible individuals that mount inappropriate immune responses to their microbiota leading to chronic intestinal inflammation. The natural history of IBD progression begins with early subclinical stages of disease that occur before clinical diagnosis. Improved understanding of those early subclinical stages could lead to new or improved strategies for IBD diagnosis, prognostication, or prevention.

Transcriptional Integration of Distinct Microbial and Nutritional Signals by the Small Intestinal Epithelium.

Background & Aims: The intestine constantly interprets and adapts to complex combinations of dietary and microbial stimuli. However, the transcriptional strategies by which the intestinal epithelium integrates these coincident sources of information remain unresolved. We recently found that microbiota colonization suppresses epithelial activity of hepatocyte nuclear factor 4 nuclear receptor transcription factors, but their integrative regulation was unknown.

Fxr signaling and microbial metabolism of bile salts in the zebrafish intestine.

Bile salt synthesis, secretion into the intestinal lumen, and resorption in the ileum occur in all vertebrate classes. In mammals, bile salt composition is determined by host and microbial enzymes, affecting signaling through the bile salt-binding transcription factor farnesoid X receptor (Fxr). However, these processes in other vertebrate classes remain poorly understood.

Transcriptional programmes underlying cellular identity and microbial responsiveness in the intestinal epithelium.

The intestinal epithelium serves the unique and critical function of harvesting dietary nutrients, while simultaneously acting as a cellular barrier separating tissues from the luminal environment and gut microbial ecosystem. Two salient features of the intestinal epithelium enable it to perform these complex functions. First, cells within the intestinal epithelium achieve a wide range of specialized identities, including different cell types and distinct anterior-posterior patterning along the intestine.

Olfactory sensory neurons mediate ultrarapid antiviral immune responses in a TrkA-dependent manner.

The nervous system regulates host immunity in complex ways. Vertebrate olfactory sensory neurons (OSNs) are located in direct contact with pathogens; however, OSNs' ability to detect danger and initiate immune responses is unclear. We report that nasal delivery of rhabdoviruses induces apoptosis in crypt OSNs via the interaction of the OSN TrkA receptor with the viral glycoprotein in teleost fish.

Under Pressure: Interactions between Commensal Microbiota and the Teleost Immune System.

Commensal microorganisms inhabit every mucosal surface of teleost fish. At these surfaces, microorganisms directly and indirectly shape the teleost immune system. This review provides a comprehensive overview of how the microbiota and microbiota-derived products influence both the mucosal and systemic immune system of fish.

Rainbow trout (Oncorhynchus mykiss) secretory component binds to commensal bacteria and pathogens.

Commensal bacteria co-exist on the mucosal surfaces of all vertebrates. The host's mucosal immune system must tolerate commensals while fighting pathogens. One of the mechanisms used by the mucosal immune system to maintain homeostasis is the secretion of immunoglobulins (Igs) across epithelial barriers, which is achieved via the polymeric immunoglobulin receptor (pIgR).