Genetically modified eggs for allergy sufferers
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Transgenic chickens lay eggs that do not contain the egg mucoprotein. So eggs can also be eaten by people with food allergies.
Hiroshima (Japan). Chicken eggs are one of the main causes of allergic reactions in humans. Symptoms of food allergy include itching of the oral mucosa, redness, and swelling of the skin, which appear within minutes to an hour after eating the food. In exceptional cases, anaphylactic shock with circulatory arrest and shortness of breath can also occur.
Researchers at Hiroshima University led by Ryo Ezaki have developed a chicken egg that people with an allergy to the protein can safely eat. According to what was published in the specialized magazine Food and chemical toxins To do this, they used genetic engineering to remove proteins from the egg that cause a food allergy. In conventional eggs, the problematic oocyte protein makes up about 11 percent of the proteins in albumin.
In order to use OVM-knockout chicken eggs as food, it is important to assess the safety of their food. In this study, we examined the presence or absence of mutated protein expression, inserted vector sequences, and off-target effects in OVM-perfused chickens by tonic-like effector nucleases. platinum transcripts (TALENs).”
Removing oviductal protein from eggs
In order to create OVM-knockout eggs, the researchers needed to identify and remove the egg mucin protein in the egg white. TALENs are designed to target a piece of RNA called exon 1, which encodes specific proteins. The eggs produced in this way were then tested to ensure that they did not have mutated egg protein, egg mucus protein, or other unwanted side effects.
The eggs contained the target frameshift mutation, a mutation caused by insertion or deletion of nucleotide bases in the gene, and none of them expressed mature oocyte mucosal proteins. Mucin oocyst and anti-mutagenic antibodies were used to search for traces of the protein, but no mucin oocyst was detected in the eggs. This means that eggs fertilized for the mutation cannot create new allergens. This is a major advance in defining the safety profile of eggs.
Hens show no abnormalities
According to Isaki, the eggs laid by the knockout hens showed no obvious abnormalities. Neither the mature OVM nor the truncated OVM variant was contained in albumin. The potential off-target effects induced by TALEN in chickens subjected to OVM conflict could be limited to regions of gene and intron overlap.
The plasmid vectors used for genome editing were transient and did not integrate into the engineered chicken genome. These findings highlight the importance of safety assessments and demonstrate that the eggs laid by these knockout hens can solve the problem of food and vaccine allergies.
Safety profile of OVM knockout eggs
Going forward, the researchers plan to further validate the safety profile of OVM-knockout eggs. Due to the fact that some people are hypersensitive to this particular protein, even small amounts of ovarian mucus can trigger a reaction. Additional immunological and clinical studies are necessary to determine the safety of OVM knockout eggs. So far, scientists have found that OVM fired eggs are less allergenic than regular eggs and are safe to use in heat-treated foods that can be consumed by egg allergy sufferers.
Isaki explained that the next stage of research involves evaluating the physical properties and addressing suitability of OVM knockout eggs, and their efficacy should be confirmed through clinical trials. He reiterated the researchers’ commitment to continue additional investigations toward the practical application of hypoallergenic eggs.
Food and Chemical Toxicology, doi: 10.1016/j.fct.2023.113703