With more than 3 billion people worldwide suffering from pathological allergic symptoms, it is no surprise that allergy research has become a top priority for pharmaceutical companies and allergy sufferers, alike. And while animal models have been used for some studies associated with allergic reactions and the potential efficacy of new allergy-related drugs, the reality is that the significant differences between the human and mouse immune systems has made it difficult for mice to effectively mimic allergic responses in humans.

 

To address this, Bryce et al have developed a new humanized mouse model that “supports human mast cell engraftment and human IgE-dependent allergic reactions,” according to a recent study published in the Journal of Allergy and Clinical Immunology. Using a strain of immunodeficient mice engrafted with human bone marrow, liver and thymus (BLT) stem cells, researchers were able to create a mouse model that allowed for in vivo investigation of human mast cell-mediated passive cutaneous anaphylaxis (PCA) and passive systemic anaphylaxis (PSA) allergic reactions.

Additionally, these BLT humanized mice models boast a large number of human mast cells within their peritoneal cavity, which can be readily cultured and used for in vivo experiments without the need for tissue digestion. This has the potential to allow researchers to better understand the process by which human mast cells trigger the production of Immunoglobulin E (IgE) antibodies and the resulting allergen induced inflammation that can lead to fatal results in patients suffering from anaphylaxis.

 

The newly created BLT humanized mouse model offers tremendous implications for the future of allergy research and gives hope that a rat model with a humanized immune system, which would likely mimic the human genetic makeup even more closely, can be developed in short order. In any case, these rodent models are sure to remain important research tools in the investigation of human mast cell biology as well as preclinical trials to determine the efficacy of new drug therapies for anaphylaxis reactions, which are so urgently needed.