Fat-associated lymphoid clusters (FALCs) are small immune structures found in certain visceral adipose tissues such as the omentum and the pericardium, which provide an important first layer of defence during infection. Our recent work show that the function of FALCs is underlaid by specialised mesothelial stromal cells which cover the surface of FALCs. During peritonitis, they drive the recruitment and formation of neutrophil aggregates which mediate the capture of peritoneal contaminants and limit systemic propagation. In addition, I will discuss recent data investigating the role of Tim4+ adipose tissue macrophages in the control of lipid metabolism. Biography Cécile Bénézech did her PhD in Nantes (France) investigating the anti-tumour activity of human  T cells. She then moved to Birmingham (UK) in the laboratory of Jorge Caamano to study the role of TNF receptors in the development of lymphoid tissue. During her time in the lab, she discovered that lymph nodes and adipose tissue are developmentally related and that during embryonic development, adipocyte precursor cells give rise to the stroma of the lymph nodes. This led her to investigate other lymphoid structures characteristics of certain fat depots and to demonstrate the importance of Fat-associated lymphoid clusters in immunity. In 2013, she was awarded a Chancellor’s Fellowship to set up her own lab in the Centre for Cardiovascular Sciences in Edinburgh. Her lab is investigating the role of visceral fat depot in the protection of serous cavities and how adipose tissue immune cells help maintain metabolic health.