Regulatory Immune Mechanisms in Tolerance to Food Allergy

Abstract

Oral tolerance can develop after frequent exposure to food allergens. Upon ingestion, food is digested into small protein fragments in the gastrointestinal tract. Small food particles are later absorbed into the human body. Interestingly, some of these ingested food proteins can cause allergic immune responses, which can lead to food allergy. So far it has not been completely elucidated how these proteins become immunogenic and cause food allergies. In contrast, oral tolerance helps to prevent the pathologic reactions against different types of food antigens from animal or plant origin. Tolerance to food is mainly acquired by dendritic cells, epithelial cells in the gut, and the gut microbiome. A subset of CD103+ DCs is capable of inducing T regulatory cells (Treg cells) that express anti-inflammatory cytokines. Anergic T cells also contribute to oral tolerance, by reducing the number of effector cells. Similar to Treg cells, B regulatory cells (Breg cells) suppress effector T cells and contribute to the immune tolerance to food allergens. Furthermore, the human microbiome is an essential mediator in the induction of oral tolerance or food allergy. In this review, we outline the current understanding of regulatory immune mechanisms in oral tolerance. The biological changes reflecting early consequences of immune stimulation with food allergens should provide useful information for the development of novel therapeutic treatments.

The Relationship between the Infant Gut Microbiota and Allergy. The Role of Bifidobacterium breve and Prebiotic Oligosaccharides in the Activation of Anti-Allergic Mechanisms in Early Life

“…Treg activation is one of the basic mechanisms of immune tolerance induction. Disturbed functioning of these cells results in a Th1/Th2 imbalance and produces an abnormal immunological response to external allergens [80].…”

Evaluation of Peptide/Protein Self-Assembly and Aggregation by Spectroscopic Methods

“…Moreover, in the food industry, the aggregation processes of whey proteins from milk [ 6 ], wheat gliadin and glutenin [ 7 ], and peanut proteins [ 8 ] are some examples that are continuously studied. The formed aggregates affect not only the organoleptic properties of the final product, but also its digestibility, bioavailability of amino acids and, in some cases, they can even induce or reduce inadequate immune responses to a toxic protein [ 9 , 10 ].…”

Cytokine profile in children with food allergy following liver transplantation

“…Specific IgE antibodies induce degranulation of mast cells and release of mediators including cytokines, histamine, and proteases which in turn result in allergic symptoms. T regulatory cells (Treg cells) can produce inhibitory cytokines such as IL‐10 and TGF‐β and play a role in developing tolerance . Therefore, identifying the pattern of cytokine expression can give valuable insight into the mechanisms of food allergy.…”

“…T regulatory cells (Treg cells) can produce inhibitory cytokines such as IL-10 and TGF-β and play a role in developing tolerance. 14 Several studies link immunosuppression and especially tacrolimus to the development of transplant-aquired food allergy (TAFA) in liver transplanted children. [2][3][4]15 Lacaille et al 2 suggested that tacrolimus induced an imbalance between the Th1 and Th2 leukocyte subsets.…”