IgE receptor of mast cells signals mediator release and inflammation via adaptor protein 14-3-3ζ

Update on mast cell biology

Mast cells (MCs) are heterogeneous tissue-resident effector cells that are thought to play central roles in allergic inflammatory disease, yet the degree of heterogeneity and nature of these roles has remained elusive. In recent years, advances in tissue culture systems, preclinical mouse models, and the continued spread of single-cell RNA sequencing have greatly advanced our understanding of MC phenotypes in health and disease. These approaches have identified novel interactions of MC subsets with immune cells, neurons, and tissue structural cells, changing our understanding of how MCs both drive and help resolve tissue inflammation, reshape tissue microenvironments, and influence host behavior. This review addresses key studies from 2022 to 2024 that have advanced our understanding of MC biology in mice and humans.

The β Common Cytokine Receptor Family Reveals New Functional Paradigms From Structural Complexities

Cytokines are small proteins that are critical for controlling the growth and activity of hematopoietic cells by binding to cell surface receptors and transmitting signals across membranes. The β common (βc) cytokine receptor family, consisting of the granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-3, and IL-5 cytokine receptors, is an architype of the heterodimeric cytokine receptor systems. We now know that signaling by cytokine receptors is not always an "all or none" phenomenon. Subtle alterations of the cytokine:receptor complex can result in differential or selective signaling and underpin a variety of diseases including chronic inflammatory conditions and cancers. Structural biology techniques, such as X-ray crystallography and cryo-electron microscopy alongside cell biology studies, are providing detailed insights into cytokine receptor signaling. Recently, we found that the IL-3 receptor ternary complex forms higher-order assemblies, like those found earlier for the GM-CSF receptor, and demonstrated that functionally distinct biological signals arise from different IL-3 receptor oligomeric assemblies. As we enhance our understanding of the structural nuances of cytokine-receptor interactions, we foresee a new era of theranostics whereby structurally guided mechanism-based manipulation of cytokine signaling through rational/targeted protein engineering will harness the full potential of cytokine biology for precision medicine.

Bee venom acupuncture and herbal medicine for hand eczema: Two case reports and an in vivo study

INTRODUCTION

Eczema and contact dermatitis are relatively common, non-life-threatening disease, but can reduce the patient's quality-of-life when it becomes chronic. This study describes two cases of bee venom acupuncture (BVA) and herbal medicine (San Wu Huangqin decoction; SWH) co-treatment for hand eczema and contact dermatitis, then confirms the effect of the combination therapy in an in vivo model of eczema.

CASE PRESENTATION

A 56-year-old female (case 1) and a 33-year-old male (case 2) presented to the clinic with symptoms of itching and erythema (case 1), and scaliness (case 2) on both hands. Both were diagnosed with hand eczema and contact dermatitis based on examination of the erythema and scaliness. They were treated with BVA and SWH for three months. The lesions were healed and had not recurred after 1 and 3 years of follow-up. A mouse study was conducted by repeated application of 2,4-dinitrochlorobenzene (DNCB) to induce eczema-like contact dermatitis in Balb/c mice. In a DNCB-induced eczema-like contact dermatitis model, BVA and SWH co-administration synergistically improved clinical symptoms seen in eczema. Also, they improved histological changes of the skin, suppressed immune cell infiltration, and decreased inflammatory cytokines and immunoglobulin E in the serum.

CONCLUSION

This study suggests BVA and SWH could be an alternative treatment for eczema and contact dermatitis.

Vitamin D Influences the Activity of Mast Cells in Allergic Manifestations and Potentiates Their Effector Functions against Pathogens

Mast cells (MCs) are abundant at sites exposed to the external environment and pathogens. Local activation of these cells, either directly via pathogen recognition or indirectly via interaction with other activated immune cells and results in the release of pre-stored mediators in MC granules. The release of these pre-stored mediators helps to enhance pathogen clearance. While MCs are well known for their protective role against parasites, there is also significant evidence in the literature demonstrating their ability to respond to viral, bacterial, and fungal infections. Vitamin D is a fat-soluble vitamin and hormone that plays a vital role in regulating calcium and phosphorus metabolism to maintain skeletal homeostasis. Emerging evidence suggests that vitamin D also has immunomodulatory properties on both the innate and adaptive immune systems, making it a critical regulator of immune homeostasis. Vitamin D binds to its receptor, called the vitamin D receptor (VDR), which is present in almost all immune system cells. The literature suggests that a vitamin D deficiency can activate MCs, and vitamin D is necessary for MC stabilization. This manuscript explores the potential of vitamin D to regulate MC activity and combat pathogens, with a focus on its ability to fight viruses.