Adipose tissue (AT) inflammation due to obesity is known to contribute to insulin resistance and/or T2D. Indeed, obese AT are known to be infiltrated with variety of immune cells. In addition to macrophages, we have recently pointed out two new actors in obesity-mediated inflammation processes, such as, adipose-derived mesenchymal stem cells (ASC) and Th17 cells. Indeed, ASC from obese, but not (or much less), lean subjects were shown to polarize interacting T cells towards the Th17 pathway, while inhibiting Th1 cell activation. Activation of monocyte/macrophages through the M1 subset was also mediated by ASC, as assessed by increased IL-1b secretion. In turn, mononuclear cell interaction with ASC resulted in increased IL-6 secretion by ASC, inhibition of adipogenesis, and decreased ASC-derived adipocyte insulin sensitivity (Eljaafari et al, 2015. Diabetes. 64:2477-88). Finally in a more recent report ( M. Chehimi et al, Adipocyte J, 2016) we have demonstrated similar pro-inflammatory properties in adipocytes harvested from obese, but not lean AT.