They describe the cells responsible for maintaining allergies over time.

Two groups of researchers have separately described a population of memory lymphocytes that may be responsible for different types of allergies in humans and persist over time: a single immune cell may be a hidden source of antibodies.

The results were published in Scientific translational medicine based on research in children and adults for common allergies, such as peanutHe dust or birchand their findings may help identify the true source of allergic memory, and these cells could serve as targets in the treatment of various types of allergies.

The first study led by Milhaud Ota Icahn School of Medicine at Mount Sinai Hospital (USA)In a group of children with peanut allergy, describe the population of immune cells that support the production of allergen-specific immunoglobulin E (IgE)an antibody that mediates many types of allergic reactions.

The researchers examined the immune cells of 58 allergic and 13 non-allergic children: the former had large numbers of a unique type of polarized type 2 IgG+ memory B cells that specifically recognized the peanut allergen (Ara h 2) and could quickly switch to producing IgE.

“The study provides interesting information about the markers and types of IgG+ memory B cells that cells must have before differentiating into highly specific IgE-producing anti-peanut protein plasma cells,” he elaborates. Africa Gonzalez Fernandez, professor of immunology at the University of Vigo and researcher at the Center for Biomedical Research (CINBIO).

“The paper shows that IgE-producing B cells are not generated directly, but rather that there has been a transition from IgM to IgG, which previously became IgE+ B cells,” he notes on the Science Media Center (SMC) platform.

This study confirms in children what has previously been observed in adults, such as in two papers from 2016 and 2020, one with peripheral blood and the other with mucosal cells, and confirms what other authors have observed.

Second investigation conducted Joshua Koening, McMaster University, Canadasimilarly concluded that the same population of polarized type 2 memory B cells also supports allergic memory.

They based their findings on a study of six adults with birch allergy; four were dust mite related and five were not allergic, adding to data from adults with peanut allergies.

They saw that these cells generate IgE against specific antigens in some patients during sublingual allergy immunotherapy, thereby demonstrating that these cells act as an important reservoir for antibodies.

“The immune system’s memory for IgE production is concentrated in plasma cells, many of which are short-lived; however, the production of specific IgE directed against the allergen can be maintained for long periods of time once awareness arises,” he elaborates. Ignacio Jesús Dávila González, Head of the Allergy Service of the University Hospital of Salamanca, Professor at the Faculty of Medicine of the University of Salamanca.

Mediator cells, immunotherapy and monoclonal antibodies

These two studies describe, more specifically, “a population of type 2 memory B cells that express IgG as well as the low-affinity receptors for IgE, FcRII or CD23, the IL-4 receptor, and the IgE heavy chain.” doctor and also President of the Spanish Society of Allergy and Clinical Immunology (SEAIC).

Importantly, these cells “appear to be able to promote the production of specific IgE (e.g., against Ara h 2 (the major peanut allergen) in the case of the first study) by differentiating into plasma cells, which may explain the maintenance of very high levels of specific IgE against Ara h 2 in some patients.”

“It seems that the administration Sublingual immunotherapy may increase the number of this type of cell. already after a month of treatment, which, in addition, may change to the production of allergen-specific IgG1 or IgG4. It is well known that the latter increases with immunotherapy with allergens,” continues the doctor.

Finally, these type 2 memory B cells express IL4 receptor alpha chain and IL13 receptor alpha 1 chain. He by blocking these receptors could be an interesting treatment induction of tolerance to allergens.

“In fact, dupilumabA monoclonal antibody Targeting the IL4 receptor alpha chain and blocking IL4 and IL3 signaling has been shown to reduce levels of total IgE and specific IgE and may lead to the development of tolerance.

Scientific translational medicine 2024 (16) 733 DOI: 10.1126/scitranslmed.adi0673.

Scientific translational medicine 2024 (16) 733 DOI: 10.1126/scitranslmed.adi0944.