The Role of Toll-Like Receptors in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: A New Promising Therapeutic Approach?

Perturbations in immune processes play an important role in chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME), a multifactorial disorder mainly characterized by severe and prolonged fatigue and tipically affecting a variety of bodily systems including the immune system. Recent reports have shown that CFS/ME is an inflammatory disorder may be associated with autoimmune responses, mainly characterized by reduced functional activity of most immune cells, including neutrophils, natural killer cells, monocytes/macrophage and dendritic cells, together with dysregulations in cytokine levels, responsible for changes in the adaptive immune system. Interactions between gut microorganisms and host immune function have been shown to contribute to aberrant inflammation in CFS/ME patients. Commensal and/or pathogen-associated molecular patterns detected by Toll-like receptors (TLRs) expressed on intestinal epithelial cells appear to trigger inflammatory signaling cascade leading to neuroinflammation and neurodegeneration. This paper examines the role of TLR-mediated innate immunity in CFS/ME with evaluation of the current literature, also discussing about innovative therapeutic approaches represented by immunomodulators TLR-targeting.