The Protective Role of Type I Interferons in the Gastrointestinal Tract.

The immune system of the gastrointestinal (GI) tract manages the significant task of recognizing and eliminating pathogens while maintaining tolerance of commensal bacteria. Dysregulation of this delicate balance can be detrimental, resulting in severe inflammation, intestinal injury, and cancer. Therefore, mechanisms to relay important signals regulating cell growth and immune reactivity must be in place to support GI homeostasis. Type I interferons (IFN-I) are a family of pleiotropic cytokines, which exert a wide range of biological effects including promotion of both pro- and anti-inflammatory activities. Using animal models of colitis, investigations into the regulation of intestinal epithelium inflammation highlight the role of IFN-I signaling during fine modulation of the immune system. The intestinal epithelium of the gut guides the immune system to differentiate between commensal and pathogenic microbiota, which relies on intimate links with the IFN-I signal-transduction pathway. The current paradigm depicts an IFN-I-induced antiproliferative state in the intestinal epithelium enabling cell differentiation, cell maturation, and proper intestinal barrier function, strongly supporting its role in maintaining baseline immune activity and clearance of damaged epithelia or pathogens. In this review, we will highlight the importance of IFN-I in intestinal homeostasis by discussing its function in inflammation, immunity, and cancer.

Two-dimensional quantum percolation with binary nonzero hopping integrals.

In a previous work [Dillon and Nakanishi, Eur. Phys. J. B 87, 286 (2014)EPJBFY1434-602810.1140/epjb/e2014-50397-4], we numerically calculated the transmission coefficient of the two-dimensional quantum percolation problem and mapped out in detail the three regimes of localization, i.e., exponentially localized, power-law localized, and delocalized, which had been proposed earlier [Islam and Nakanishi, Phys. Rev. E 77, 061109 (2008)PLEEE81539-375510.1103/PhysRevE.77.061109]. We now consider a variation on quantum percolation in which the hopping integral (w) associated with bonds that connect to at least one diluted site is not zero, but rather a fraction of the hopping integral (V=1) between nondiluted sites. We study the latter model by calculating quantities such as the transmission coefficient and the inverse participation ratio and find the original quantum percolation results to be stable for w>0 over a wide range of energy. In particular, except in the immediate neighborhood of the band center (where increasing w to just 0.02Vappears to eliminate localization effects), increasing w only shifts the boundaries between the three regimes but does not eliminate them until w reaches 10%-40% of V.