Fructose intake enhances lipoteichoic acid-mediated immune response in monocytes of healthy humans

Metabolic diseases like type 2 diabetes are afflicted with higher rates of infections and longer, more complicated infection course as well as higher fatality rates. The impact of nutrition and specific nutrients like free fructose herein has not yet been fully understood. Here, we performed dietary intervention studies in healthy individuals and performed ex vivo experiments in isolated blood immune cells to assess the effects of dietary fructose intake on Gram-positive bacterial toxin induced immune responses. Acute and extended intake of fructose but not glucose was related with an induction of Toll like receptor 2 mRNA expression in monocytes and enhanced the LTA-dependent release of proinflammatory cytokines from monocytes. Blocking fructose metabolism and transcription factor SP1 attenuated the fructose-related induction of Toll like receptor 2 mRNA expression and augmentation of proinflammatory cytokine release further suggesting that fructose-dependent metabolic alterations are critical in enhancing immune responsiveness of humans after fructose consumption.