Figure 1.

Effects of leptin on human B cell function. Leptin is secreted by adipocytes in the AT. Leptin concentration increases locally and systemically under obesity conditions. Leptin interacts with its receptor on the surface of B cells and increases mRNA expression of several markers of inflammation and cellular senescence, such as TNF-α, IL-6, IL-8, miR-155, miR-16, TLR4, and p16. The expression of these mediators in unstimulated B cells is negatively associated with the response of the same B cells after in vivo/in vitro stimulation, e.g., with the influenza vaccine.