Thursday Seminar: Agathe Depaire

Presentation entitled: “Endothelial cells-induced macrophages with efferocytosis alteration in systemic sclerosis” Resume: “Systemic sclerosis is a rare chronic autoimmune disease involving exaggerated fibrosis of the skin and internal organs, vasculopathy and dysregulation of the immune system. Data suggest that IL-1b is an important effector in lung and skin inflammation and fibrosis. However, evidences in human systemic sclerosis still scarce and the mechanisms involved are not fully understood. We showed that IL-1β-activated endothelial cells are able to skew differentiation of monocytes toward M2-like macrophages endowed with pro-inflammatory functions. Those macrophages are associated to fibrosis, but the mechanisms are still unclear. Alternative macrophages are able to phagocytose apoptotic cells by the mechanism known as efferocytosis. A defect in this process results in chronic inflammation and fibrosis, notably mediated by an accumulation of apoptotic cells leading to secondary necrosis in the tissues. We want o study whether endothelial cells-induced macrophages efferocytosis is altered during systemic sclerosis and contribute to fibrosis. “