Research sheds new light on the allergic response – and how to disrupt it

Dendritic cells are an essential component of the immune system. These ‘sentinels’ patrol the body, constantly sampling the environment for signs of infection or damage. When they detect pathogens, such as a bacteria or viral particle, they engulf them, travelling to the nearest lymph node to present their findings to T-cells, which then launch an appropriate immune response.

However dendritic cells can also present harmless things like pollen, peanuts or soy to the immune system as if they are as harmful as a virus, kicking of an allergic response – a process that typically first develops in early childhood and can continue throughout the lifetime. 

Once dendritic cells have presented their findings to the immune system, their role is complete. The cells often initiate ‘apoptosis’ – or programmed cell death – and are replaced by new dendritic cells produced in the bone marrow. 

“Previous research in the Ronchese lab found that there is a steady population of allergy-inducing dendritic cells in the skin.  The development of these cells is supported by a chemical signalling molecule called IL-13, which is present even when there’s no active inflammation,” says Senior Research Fellow Dr Sotaro Ochiai.  

The lab’s latest findings, published in The Journal of Investigative Dermatology, go one step further to look at how these cells are replenished following their migration to the lymph node during active allergic skin inflammation.

“We followed these cells over time to understand how they returned to the skin and what is needed to replenish them. We found that IL-4, a molecule related to IL-13, was important for this mechanism and contributes to the persistence of allergic diseases.”

What causes dendritic cells to pick up allergens and present them to the immune system as a threat is still unknown. However, being able to disrupt this cycle in places like the skin may interrupt the allergic response.

“In the Ronchese lab, our allergy research focuses on two main goals. One is preventing the development of allergies in the first place, the other is finding ways to interrupt existing allergic responses. We hope that this kind of research might one day lead to novel strategies to provide relief for people suffering from allergic disease.”