Cutting out Allergies: Gene Editing in Preventing Allergic Reactions

BY JUSTIN HUANG

Allergies are one of the most common ailments affecting people worldwide, with over a quarter of adults and approximately one in five children reporting at least one seasonal allergen, in addition to those who report food allergies and cases of eczema. You have more likely than not experienced some degree of allergic reaction, and if you haven’t, you likely know someone who has. It’s not a pleasant experience by any means, and you likely wish they wouldn’t happen. What if they didn't? With the development of large-scale genetic amplification through techniques such as polymerase chain reactions (PCR), which is basically a method to create many copies of a single segment of DNA, many allergic reactions were found to have a genetic component. Additionally, other gene-editing technologies such as CRISPR-Cas9 have also seen more prevalent use in the last few years. Using such techniques, many genes for different allergens have been identified, and these studies may be used for personalized treatment and even cures.

Recent studies using CRISPR-Cas9 have been able to identify and cut out allergen inducing genes in-vitro, and then reduce the amount of allergens that each organism produces by selectively distributing the edited genomes to their respective organisms. For example, say you were allergic to peanuts or other peanut-related products. These products contain a protein called Ara h 2, which would be responsible for your allergic reactions to these products. Using methods to reduce the expression of this protein, scientists were able to reduce the amount of Ara h 2 found in treated peanut plants by a quarter. Further research and development with CRISPR-Cas9 technology aims to completely delete allergen-inducing genes such as Ara h 2, potentially eliminating human exposure to compounds that may induce fatal allergic reactions.

What if instead of removing or avoiding your allergens, you just didn’t react to them? Targeting of human genes that code for proteins that identify allergen-inducing compounds is also a potentially viable alternative to reducing the severity of allergic reactions. For example, complete deletion of genes such as CYP11A1 and proteins such as IL-4 and IL-13, other major contributors to peanut-based allergies found in our cells, can in turn delete the proteins responsible for causing allergic reactions in humans, reducing allergenicity.

Despite the promising developments of CRISPR-Cas9 gene editing in the treatment of allergies and other related conditions, just remember that this is a relatively new treatment technique, and that there are still many obstacles to clear. In particular, there may still be some difficulties in transporting CRISPR-Cas9 gene editing elements into the proper cells within our bodies. However, just imagine a future where allergies are a thing of the past. This could be the start of making that happen.

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Brackett NF, Pomés A, Chapman MD. New Frontiers: Precise Editing of Allergen Genes Using CRISPR. Front Allergy. 2022 Jan 17;2:821107. doi: 10.3389/falgy.2021.821107. PMID: 35386981; PMCID: PMC8974684.

Meiqin Wang, Michaela Schedel, Erwin W. Gelfand. Gene editing in allergic diseases: Identification of novel pathways and impact of deleting allergen genes. Journal of Allergy and Clinical Immunology. Volume 154, Issue 1. 2024. Pages 51-58. ISSN 0091-6749. https://doi.org/10.1016/j.jaci.2024.03.016.