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.

Two key players in the immune system, dendritic cells (DCs) and innate lymphoid cells (ILCs), interact in a crucial way to fight infectious diseases. DCs play a key role in recognizing pathogens, and ILCs respond to cytokines released by DCs. This response triggers the production of specific effector cytokines that help control pathogens and maintain the body’s barrier integrity. DCs have various receptors, including Toll-like receptors (TLRs), that detect microbial components and trigger immune responses. Likewise, ILCs act as essential initial responders in the immune system in viral, bacterial, and parasitic infections. Successfully managing diseases caused by pathogens mainly depends on the combined actions of DCs and ILCs, which work to suppress and eliminate pathogens. DCs also play a crucial role in activating innate and adaptive immune cell subsets, including ILCs. Furthermore, the use of DCs in developing vaccines and immunotherapy for cancers, along with the dedication of many researchers to improve immune responses through DCs, has increased interest in the potential of DC therapies for treating and preventing infectious diseases. This review examines approaches that may enhance DC vaccines and boost anti-infection immune responses by fostering better interactions of DCs with ILCs.

The skin is a dynamic organ with a complex immune network critical for maintaining balance and defending against various pathogens. Different types of cells in the skin, such as mast cells (MCs) and group 2 innate lymphoid cells (ILC2s), contribute to immune regulation and play essential roles in the early immune response to various triggers, including allergens. It is beneficial to dissect cell-to-cell interactions in the skin to elucidate the mechanisms underlying skin immunity. The current manuscript concentrates explicitly on the communication pathways between MCs and ILC2s in the skin, highlighting their ability to regulate immune responses, inflammation, and tissue repair. Furthermore, it discusses how the interactions between MCs and ILC2s play a crucial role in various skin conditions, such as autoimmune diseases, dermatological disorders, and allergic reactions. Understanding the complex interactions between MCs and ILC2s in different skin conditions is crucial to developing targeted treatments for related disorders. The discovery of shared pathways could pave the way for novel therapeutic interventions to restore immunological balance in diseased skin tissues.