Egg allergies, especially in children, are widespread and can be triggered by various food products and even vaccines. However, a breakthrough has been made by researchers who utilized genome editing technology to create a chicken egg that might be safe for individuals with egg allergies to consume.
The immune system’s hyperactive response to the protein present in eggs is responsible for egg allergies. Allergies can manifest towards either the egg white or the yolk, but allergies to egg whites are more prevalent. Typically, children tend to outgrow their egg allergies before reaching adolescence, although exceptions do exist. Symptoms of egg allergy can vary from person to person but often include skin inflammation, nasal congestion, stomach discomfort, difficulty breathing, and in severe cases, anaphylaxis—an acute allergic reaction that necessitates immediate medical attention.
Interestingly, a surprising number of food products contain eggs or egg derivatives, such as egg powder or dried eggs. This includes items like breaded and battered foods, Caesar salad dressing, crepes and waffles, ice cream, candy, meatloaf and meatballs, marshmallows, and marzipan.
Furthermore, most flu vaccines are manufactured using egg-based technology. To tackle this issue, researchers from Hiroshima University turned to genome editing technology called TALENs. Transcription activator-like effector nucleases (TALENs) are synthetic enzymes specifically designed to cleave DNA at targeted sequences, causing the DNA strands to break. The cellular repair mechanism then initiates to reconnect the broken strands.
Compared to other gene editing techniques like CRISPR, TALENs offer the advantage of avoiding “off-target” effects, which can induce unintended mutations during the editing process. In this particular case, off-target effects could potentially create mutant versions of the OVM protein, leading to continued allergic reactions.
The scientists employed TALENs to disrupt exon 1 of the RNA in hens, which is responsible for coding specific proteins. They examined the resulting eggs laid by these genetically modified hens to determine the presence of the troublesome OVM protein, mutant OVM protein, or any other off-target effects.
Remarkably, the eggs showed no noticeable abnormalities and contained no traces of OVM or mutant variants of the protein. While the whole genome sequencing of the modified eggs revealed mutations, these mutations did not affect the regions responsible for coding proteins.
“These results highlight the importance of safety assessments and demonstrate that the eggs laid by this OVM knockout chicken can resolve the allergy problem associated with food and vaccines,” said lead author of the study, Ryo Ezaki.
Recognizing that even minute amounts of OVM can trigger allergic reactions in some individuals, the researchers are cautiously optimistic in stating that the modified eggs are less allergenic than regular eggs, pending further confirmation through additional testing.
The next phase of research will involve evaluating the physical characteristics and suitability for processing the OVM-knockout eggs, as well as confirming their effectiveness through clinical trials.
Ezaki expressed the team’s commitment to conducting further research aimed at practical applications of eggs with reduced allergenic potential.
This breakthrough holds significant promise for addressing egg allergies in both food products and vaccines. Although further evaluations and clinical trials are necessary, the researchers are optimistic about the potential of these modified eggs to mitigate allergies.
The study’s findings were published in the journal Food and Chemical Toxicology.
Source: Hiroshima University