Microbiota, regulatory T cell subsets, and allergic disorders

Abstract

Epidemiologic studies revealed a crucial role of the environment for the increased prevalence of allergic disorders. e microbiota as part of our immediate environment promotes immune diversity that facilitates a well-equilibrated balance between immunity and tolerance. Alterations of our symbiotic microbiota especially in early life is thought to play a fundamental role in de ning susceptibility to the development of allergic diseases during adult life on the population level. Due to a high density of bacteria, viruses and fungi and a large contact surface area for host-microbiota interactions, the most relevant interaction between microbes and our immune system are thought to occur in the gut. e immune system co-evolved with the symbiotic microbiota and adopted a variety of mechanisms to allow a dynamic state of tolerance, including the induction of regulatory T cells (Tregs). Foxp3-expressing Tregs are welldescribed immune regulators in autoimmune and allergic disorders. However, recent years have shown that Tregs can come in di erent avours with di erent regulatory potential and outcome for our immune system. is review summarizes novel ndings from basic immunology research that may help to better understand the interaction between the microbiota, di erentiation of Tregs and its consequences for the onset and regulation of allergic disorders.Cite this as Ohnmacht C. Microbiota, regulatory T cell subsets, and allergic disorders. Allergo J Int 2016;25:114-23

Interplay between severities of COVID-19 and the gut microbiome: implications of bacterial co-infections?

“…This is of particular interest based on evidence from previous studies that link gut microbiome and lung immunity [26]. Intestinal microbial dysbiosis modulates the immune responses of neutrophils, T-cell subsets, inflammatory cytokines, and Toll-like receptors thereby influencing pulmonary dysfunction [27][28][29][30][31]. Similarly, during an infection of the respiratory tract, the commensal microbes in the host lung stimulate local (lung) and distal (gut) immune responses [32].…”

The developing gut microbiota and its consequences for health

“…40 This immature Th2-dominant neonatal response undergoes environment-driven maturation via microbial contact during the early postnatal period, leading to the development of intestinal barrier functions and of regulatory T cell and a Th balance. 41,42 Moreover, the immune system appears to be regulated by microbiota in a time restricted period during early life and to be influenced by the maternal microbiota. 43,44 Alterations in the sequential establishment of gut microbiota observed in western countries could therefore be responsible for a Th balance deviation toward a Th2 profile, a major factor in the rise of allergic diseases.…”

Protease‐activated receptor‐2 suppresses interleukin (IL)‐10 expression in B cells via upregulating Bcl2L12 in patients with allergic rhinitis

“…Another pathological feature of allergy is the compromise of immunotolerance . The immunotolerance system in the body includes the immunoregulatory cells, such as regulatory T cells (Treg) and regulatory B cells (Breg), and the cytokines produced by immunoregulatory cells . Tregs have been extensively studied, while the mechanism by which Bregs regulate allergic response remains to be further investigated.…”