Chronic & Non-communicable Diseases

AXA Chairs


A New Driver of Immune Diseases: The Many Faces of B Cells

The human immune system is a wondrous thing, flexible enough to adapt to innumerable assaults that come its way, while neutralizing each with precision. Occasionally, though, glitches do occur, leading to autoimmune diseases, like multiple sclerosis or type 1 diabetes, or chronic allergy. These are increasingly prevalent conditions, which usually start in children or young adults and subsequently last for a lifetime. Science has uncovered a great deal about these diseases, but now the paradigm is shifting regarding the role of different actors of the immune system and Prof. Simon Fillatreau is a pioneer in this field. His goal is to understand the diverse class of immune cells that he believes drives such diseases and to bring this pre-clinical knowledge to the patient’s bedside.
Prof. Fillatreau’s focus is the immune system’s B cells. Certain members of their ranks produce antibodies specific to each foreign invader; others display samples of those invaders to other cells that will destroy them. Treatments depleting B cells have had a positive effect in patients with some autoimmune diseases, suggesting they play a role in causing disease. Prof. Fillatreau was among the first to show that a key culprit was a third type of B cell, one producing molecular messengers, called cytokines, that affect the behavior of other cells. Those messengers that promote inflammation actually drive the development of certain diseases that, until now, everyone had attributed solely to another actor of the immune system, the T cells.

Armed with the new vision that B cells, acting via cytokines, trigger other cells, including T cells, to cause disease, Prof. Fillatreau wants to make more targeted therapies possible by better characterizing the members of the B cell family. This is critically important because although some of the cytokine-producing cells may drive disease, it is also known that others have a protective function. Working with multiple sclerosis patients in the clinical lab, his goal is to identify markers for the different B cell subsets, to avoid depleting the helpful ones when eliminating the undesirable ones. Monitoring patients’ B cell populations could help predict who will benefit from B cell depletion therapy, too. He will also investigate what the disease-causing T cells do when their driver B cells are more active, or when protective B cells are less active, as is the case in multiple sclerosis. He believes a new group of pathogenic T cells might emerge in such a case, something no one has looked for before.

As the project advances, Prof. Fillatreau will build on this new knowledge of B cells to understand their role in allergy, too. The prevalence of chronic allergies is on the rise – the world health organization predicts that 50% of the world population will suffer from at least one allergy by 2050 – and B cells, via their cytokines, might also have a hand in their development. His objective is to develop a center devoted to opening eyes to the diverse and unexplored roles played by B cells and to creating innovative therapeutic tools for a host of immune conditions with a heavy impact on human health.

Scientific title : AXA Chair in Translational Immunology

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Université Paris Descartes

Université Paris V





ORCID Open Researcher and Contributor ID, a unique and persistent identifier to researchers