The Multifaceted Roles of Mast Cells in Immune Homeostasis, Infections and Cancers

Abstract

Mast cells (MCs) play important roles in normal immune responses and pathological states. The location of MCs on the boundaries between tissues and the external environment, including gut mucosal surfaces, lungs, skin, and around blood vessels, suggests a multitude of immunological functions. Thus, MCs are pivotal for host defense against different antigens, including allergens and microbial pathogens. MCs can produce and respond to physiological mediators and chemokines to modulate inflammation. As long-lived, tissue-resident cells, MCs indeed mediate acute inflammatory responses such as those evident in allergic reactions. Furthermore, MCs participate in innate and adaptive immune responses to bacteria, viruses, fungi, and parasites. The control of MC activation or stabilization is a powerful tool in regulating tissue homeostasis and pathogen clearance. Moreover, MCs contribute to maintaining the homeostatic equilibrium between host and resident microbiota, and they engage in crosstalk between the resident and recruited hematopoietic cells. In this review, we provide a comprehensive overview of the functions of MCs in health and disease. Further, we discuss how mouse models of MC deficiency have become useful tools for establishing MCs as a potential cellular target for treating inflammatory disorders.

The mast cell reaction in premalignant and malignant lesions of the head and neck

“…Maybe the best example is represented by the anti-angiogenic and anti-vascular therapy, which if efficient, consistently reduces the dimensions of the tumor. Changes induced by MC degranulation versus inhibitor drugs of degranulation in both experimental models and medical practice are largely unexplored [28].…”

“…Maybe the best example is represented by the anti-angiogenic and anti-vascular therapy, which if efficient, consistently reduces the dimensions of the tumor. Changes induced by MC degranulation versus inhibitor drugs of degranulation in both experimental models and medical practice are largely unexplored [ 28 ]. Numerous plant extracts, such as the total leaf extract of Melissa officinalis, have multiple benefits (antioxidant, antimicrobial, antiangiogenic and cytotoxic effects) as a potentiating agent in chemoprevention in oral cancers [ 29 ].…”

Extracellular Vesicle-Based SARS-CoV-2 Vaccine

“…Humans are equipped with two types of immune systems to defend against foreign bodies, such as bacteria and viruses: innate immunity and acquired immunity [ 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 ]. Innate immunity is a mechanism whereby the body defends itself by recognizing the general characteristics of invading viruses and bacteria, which are then phagocytized by phagocytizing cells, such as white blood cells, neutrophils, and macrophages.…”

How Our Microbiome Influences the Pathogenesis of Alopecia Areata

“…In addition, the connective tissue of the hair follicle is heavily populated with macrophages and mast cells. Bacteria-derived metabolites stimulate keratinocytes, as mentioned above, and these can secrete growth factors for mast cells [ 109 ], which are cells with antibacterial capacity, and so they influence the modeling of the microbiota of the hair follicle [ 110 ]. In addition, Langerhans cells located mainly in the upper part of the hair follicle (a region where the IP is not yet widely evident) extend their dendrites between the keratinocytes to capture and process bacteria-derived antigens and present them to T-cells.…”