Increased activation and cytokine secretion in B cells stimulated with leptin in aged humans.

Aging is associated chronic inflammation and autoimmunity, and increased levels of leptin. Increased levels of leptin are associated with inflammation and autoimmunity. We have recently reported that leptin activates B cells to induce secretion of proinflammatory and anti-inflammatory cytokines. Role of B cells and leptin in inflammation associated with aging has not been explored. In this study we demonstrate that leptin activates and induces significantly greater amount of IL-6, TNF-α, and IL-10 by B cells from aged humans as compared to young controls. This is associated with increased leptin-induced phosphorylation of STAT3 (signal transducer and activator of transcription-3) in B cells from aged humans as compared to young subjects. These data suggest that leptin-induced B cell-derived proinflammatory cytokines may play a role in chronic inflammation associated with human aging.