Mast cells are well-known components of the innate immune system. These effector cells regulate homeostatic and disease processes through the release of preformed and de novo synthesized mediators.

The mediators include lipid mediators, such as prostaglandins and leukotrienes; preformed mediators, such as histamine, heparin and proteases; and signaling molecules such as cytokines, chemokines and various growth factors. They play a wide range of roles, from recruiting and activating other immune cells to aiding with phagocytosis and antimicrobial activity. They even help degrade snake venom!

With these different functions, mast cell biology as well as mast cells’ role in regulating healthy and disease states are important areas of research for many scientists. The list includes those studying mast cell-specific diseases such as mast cell leukemia, mastocytosis, mast cell sarcoma and mast cell activation syndrome, as well as autoimmune diseases including interstitial cystitis, inflammatory bowel disease, rheumatoid arthritis, psoriasis and multiple sclerosis. Researchers are also studying mast cells to develop a better understanding of everything from allergies and asthma to wound healing and the stress response.

All of this means mast cells are a pretty well-known entity. But with even the most familiar of cells, there’s always more to learn. Here are four facts you might not know about mast cells.

1. Mast cells are named after the German word for “overfed”

Mast cells were first described in 1878 by the German scientist Paul Ehrlich, in his doctoral thesis. He named them “mastzellen” after the German word meaning overfed (“mast”), due to the cell’s characteristic intracellular granules. In 1908, Dr. Ehrlich was awarded the Nobel Prize in Physiology or Medicine for his work on immunity.

2. Mast cells are divided into two different sub-types

Mast cells are derived from bone marrow cells and mature in the tissue into two different subtypes – mucosal or connective tissue. The two types are characterized by their protease content. Both mucosal and connective tissue mast cells are situated at the host-environment interface (mucosal tissue and skin, respectively) and are associated with blood vessels and nerves.

3. Always use Carnoy’s solution when staining for mucosal mast cells

When fixing tissue to stain for the presence of mucosal mast cells, it is best to use Carnoy’s solution over formalin-based fixatives – the same tissue stained with formalin will show fewer mucosal mast cells than when it is fixed with Carnoy’s solution. The exact reason is unknown, but researchers have theorized it may have to do with how formalin affects the intracellular granules in mucosal mast cells.

4. There are currently three main human mast cell lines used for research

 Current models for studying human mast cell biology include mast cells derived from cord blood or peripheral blood hematopoietic progenitor cells, as well as three human mast cell lines: HMC-1, LAD2 and LUVA. Each cell line comes with its own pros and cons; for example, HMC-1s are known to lack important mast cell protease and receptor expression and the LAD2 cell line can be difficult to grow and inconsistent. Kerafast offers the LUVA cell line, which can be easily cultured without growth factors to express high levels of FcεRI (the high-affinity IgE receptor) and various mast cell mediators.

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