Transferring allergies in the womb

Scientific developments in understanding food allergy prevention, diagnosis, and treatment

Food allergies (FAs) are adverse immune reactions to normally innocuous foods. Their prevalence has been increasing in recent decades. They can be IgE-mediated, non-IgE mediated, or mixed. Of these, the mechanisms underlying IgE-mediated FA are the best understood and this has assisted in the development of therapeutics. Currently there are two approved drugs for the treatment of FA, Palforzia and Omalizumab. Palfornia is a characterized peanut product used as immunotherapy for peanut allergy. Immunotherapy, involves exposure of the patient to small but increasing doses of the allergen and slowly builds immune tolerance to the allergen and increases a patient's allergic threshold. Omalizumab, a biologic, is an anti-IgE antibody which binds to IgE and prevents release of proinflammatory allergenic mediators on exposure to allergen. Other biologics, investigational vaccines, nanoparticles, Janus Kinase and Bruton's tyrosine kinase inhibitors, or DARPins are also being evaluated as potential therapeutics. Oral food challenges (OFC) are the gold standard for the diagnosis for FA. However, they are time-consuming and involve risk of anaphylaxis; therefore, alternative diagnostic methods are being evaluated. This review will discuss how the immune system mediates an allergic response to specific foods, as well as FA risk factors, diagnosis, prevention, and treatments for FA.

Food Allergens: When Friends Become Foes-Caveats and Opportunities for Oral Immunotherapy Based on Deactivation Methods

Food allergies represent a serious health concern and, since the 1990s, they have risen gradually in high-income countries. Unfortunately, the problem is complex because genetic, epigenetic, and environmental factors may be collectively involved. Prevention and diagnoses have not yet evolved into efficacious therapies. Identification and control of allergens present in edible substances hold promise for multi-purpose biomedical approaches, including oral immunotherapy. This review highlights recent studies and methods to modify the otherwise innocuous native proteins in most subjects, and how oral treatments targeting immune responses could help cancel out the potential risks in hypersensitive individuals, especially children. We have focused on some physical methods that can easily be conducted, along with chemo-enzymatic modifications of allergens by means of peptides and phytochemicals in particular. The latter, accessible from naturally-occurring substances, provide an added value to hypoallergenic matrices employing vegetal wastes, a point where food chemistry meets sustainable goals as well.

Mast cells-fetal mast cells crosstalk with maternal interfaces during pregnancy: Friend or foe?

Mast cells (MC) are hematopoietic immune cells that play a major role during allergic reactions in adults by releasing a myriad of vasoactive and inflammatory mediators. MC seed all vascularized tissues and are most prominent in organs with a barrier function such as skin, lungs, and intestines. These secreted molecules cause mild symptoms such as localized itchiness and sneezing to life-threatening symptoms (i.e., anaphylactic shock). Presently, despite the extensive research on Th2-mediated immune responses in allergic diseases in adults, we are still unable to determine the mechanisms of the role of MC in developing pediatric allergic (PA) disorders. In this review, we will summarize the most recent findings on the origin of MC and discuss the underappreciated contribution of MC in the sensitization phase to maternal antibodies during pregnancy in allergic reactions and other diseases such as infectious diseases. Then, we will lay out potential MC-dependent therapeutic strategies to be considered in future investigations to understand the remaining gaps in MC research for a better quality of life for these young patients.

Human IgE does not bind to human FcRn

The neonatal Fc receptor (FcRn) is known to mediate placental transfer of IgG from mother to unborn. IgE is widely known for triggering immune responses to environmental antigens. Recent evidence suggests FcRn-mediated transplacental passage of IgE during pregnancy. However, direct interaction of FcRn and IgE was not investigated. Here, we compared binding of human IgE and IgG variants to recombinant soluble human FcRn with β2-microglobulin (sFcRn) in surface plasmon resonance (SPR) at pH 7.4 and pH 6.0. No interaction was found between human IgE and human sFcRn. These results imply that FcRn can only transport IgE indirectly, and thereby possibly transfer allergenic sensitivity from mother to fetus.