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The integrity, or barrier function, of the intestinal epithelium is of paramount importance in -maintaining good health. This is largely imparted by a single layer of epithelial cells linked by the transmembrane tight junction protein complex near their apical surface. Disruption of epithelial permeability via the tight junctions can contribute to disease progression. The cytokine IFNγ is involved in many inflammatory processes and has been shown to dramatically increase permeability via changes at the tight junction in experimental models. One of its key effectors is the transcription factor, -IRF-1. In our studies of the role of IRF-1 in barrier function using the human T84 intestinal epithelial cell monolayer model, we have found that induction of IRF-1 alone is insufficient to change permeability and that if IRF-1 is involved in mediating the permeability effects of IFNγ, then other factors must also be required.

Controversy exists regarding the timing of the introduction of allergic foods into the diet. We investigated the immune response of rat pups exposed to beta-lactoglobulin (BLG), one of the main allergenic proteins in cow milk. Brown Norway allergy-prone rats were allocated into groups: dam-reared and unchallenged (DR), DR challenged with BLG via gavage (11 mg/d), or rats fed via gastric cannula a formula containing BLG (11 mg/d). BLG was given from d 4 of life. Rats were killed at d 10, 14, or 21. Sera were assayed for total IgE, BLG-specific IgG1, and rat mucosal mast cell protease II (RMCPII; indicator of mucosal mast cell degranulation). Ileum was assessed for cytokine mRNA. Mesenteric lymph nodes (MLN) were assessed for forkhead boxP3 (Foxp3) and chemokine (C-C motif) receptor 7 (CCR7) expression by real-time PCR and immunostained for Foxp3(+) CD4(+) regulatory cells. Formula feeding compared with dam-rearing with or without oral BLG challenge resulted in significantly greater serum IgE, BLG-specific IgG1, RMCPII, and intestinal mast cells but reduced MLN Foxp3(+) cells, Foxp3, and CCR7 expression and ileal cytokines, interleukin (IL)-4, IL-10, and interferon-gamma (P < 0.05). Importantly, giving BLG in the presence of maternal milk resulted in an immune response profile similar to that of unchallenged DR rats but with greater Foxp3 and CCR7 mRNA expression and CD4(+) Foxp3(+) cells (P < 0.05). We conclude that introducing an allergenic food with breast milk reduces immunological indicators of an allergic response, whereas introduction during formula feeding generates an allergic response.

Background: Consumption of baked egg by raw egg allergic children is associated with immune changes suggesting development of tolerance. However, causation has not been tested using a double blind randomized controlled trial (RCT). We aimed to compare clinical and immunological outcomes after baked egg (BE) consumption in young BE tolerant egg allergic children.

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