Thetis Cells

A clinical trial published in 2015 revealed that children who were exposed to peanuts at a young age were 81% less likely to develop peanut allergies than their peanut-avoidant counterparts. The children who ate peanuts were then instructed to avoid them completely for a year, yet they still didn’t develop peanut allergies. Almost a decade later, scientists finally found an explanation for this phenomenon: thetis cells. 

The immune system protects the body from hazardous substances such as bacteria and viruses; however, allergies occur when the system mistakenly identifies an allergen as a threat. Thetis cells were identified in May of 2022 as a class of immune cells that play an essential role in regulating allergic reactions to food. These cells train the immune system to differentiate between helpful bacteria and harmful pathogens, but scientists wondered if they were responsible for allergic reactions to food as well. Their hypothesis reigned true — when exposed to ovalbumin, a common allergen found in eggs, thetis cells took up the protein and programmed food-specific peripheral regulatory T cells to suppress an inflammatory response. These T cells are a specialized type of immune cell that helps prevent the immune system from overreacting to harmless food proteins. 

When mice of various ages were exposed to ovalbumin, scientists found that the number of regulatory T cells generated in adolescents was about eight times higher than in adults, so the young mice were able to maintain a food tolerance to eggs for a longer amount of time. Since thetis cell behavior in mice is extremely similar to humans, their findings could be applied to human children as well. The results of this experiment shows that there are more thetis cells in early life compared to adulthood, and there is a critical window of time where infants should be introduced to common food allergens. If this guideline is widely implemented, it could prevent tens of thousands of cases of peanut allergies among the 3.6 million children born in the United States each year.

The discovery of thetis cells has made a huge impact on pediatric allergy care, opening the door to pediatric interventions that could prevent food allergies before they develop. Researchers are currently investigating therapies designed to enhance thetis cell function as a method to treat allergies. 

Scientific advancements have allowed humans to make a plethora of discoveries about outer space, the deep ocean, and places that humanity otherwise cannot explore themselves. However, some of the most profound discoveries have come from something even more vast and complex — the intricacies of the human body. Thetis cells have deepened our understanding of how allergens affect our body, and have paved the way for treatment therapies for food-associated allergic and inflammatory diseases.

References:

Akagbosu, Blossom, et al. “Novel Antigen-Presenting Cell Imparts Treg-Dependent Tolerance to Gut Microbiota.” Nature, vol. 610, no. 7933, 1 Oct. 2022, pp. 752–760, www.nature.com/articles/s41586-022-05309-5, https://doi.org/10.1038/s41586-022-05309-5.

Demsky, Ian. “Immune “Thetis” Cells Linked to Food Allergy Prevention in Early Life.” Allergic Living, 17 May 2025, www.allergicliving.com/2025/05/17/immune-thetis-cells-linked-to-food-allergy-prevention-in-early-life/. Accessed 24 Aug. 2025.

“Key Player in Childhood Food Allergies Identified: Thetis Cells.” ScienceDaily, 2025, www.sciencedaily.com/releases/2025/05/250515141534.htm.

Leifman, Laura. “Introducing Peanut in Infancy Prevents Peanut Allergy into Adolescence.” National Institutes of Health (NIH), 28 May 2024, www.nih.gov/news-events/news-releases/introducing-peanut-infancy-prevents-peanut-allergy-into-adolescence.

“MSK Researchers Identify Key Player in Childhood Food Allergies: Thetis Cells.” Memorial Sloan Kettering Cancer Center, 15 May 2025, www.mskcc.org/news/msk-researchers-identify-key-player-in-childhood-food-allergies-thetis-cells. Accessed 24 Aug. 2025.

www.ushealthconnect.com, Home . “Thetis Cells and Pediatric Allergy Care.” Reachmd.com, reachmd.com, 6 June 2025, reachmd.com/news/thetis-cells-revolutionizing-pediatric-allergy-care/2475049/. Accessed 24 Aug. 2025.

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