Trained first as a biologist then as endocrinologist and as an immunologist, I acquired a broad expertise ranging from molecular biology to physiopathology. In the field of immunology, I and my group made seminal contributions in the understanding of the cellular and molecular mechanism of allergic diseases and immunoregulation. Early studies were focused the role of the high affinity IgE receptors and low affinity IgG receptors in anaphylactic reactions and intestinal inflammation using gene-deficient and humanized models for the various chains of these receptors. We then focused on the contribution of polynuclear eosinophils in allergic asthma and atopic dermatitis, both in humans and in animal models and at immunoregulation of theses pathologies as well as anaphylaxis in particular through prostaglandin receptors, nuclear receptors (PPAR) and chemokine receptors. More recent work has been devoted to immunometabolism and to the regulation of immune function by "metabolic" nuclear receptors (the bile acid receptor, FXR, and RORa). We recently demonstrated the role of fatty acids in the modulation of innate immune responses including in psoriasis. Taking advantage of our combined expertise in the field of skin inflammation and metabolism we are further investigating the basic mechanisms underlying comorbidities between psoriasis and metabolic diseases. Finally, we study the contribution of immune cells to Metabolically-Associated Steatotic Liver Diseases and their cardiovascular complications.