Toll like receptor 4 (TLR 4) expression on peripheral blood mononuclear cells (PBMCs) among patients with Graves disease

Abstract

Toll-like receptors (TLRs) is a family of pattern recognition receptors (PRRs) that form the cornerstone of the innate immune response. They can recognize both the external pathogen-associated molecular patterns (PAMPs) and the internal damage-associated molecular patterns (DAMPs). They are expressed on all innate immune cells such as macrophage, neutrophils, dendritic cells (DCs), natural killer (NK) cells, mast cells, basophils, and eosinophil. TLR activation stimulates signaling cascades by the host as a defense mechanism against invaders and to repair the damaged tissue, leading to the release of various inflammatory cytokines and immune modulators. Excessive TLR activation disrupts the immune homeostasis by sustained pro-inflammatory cytokines and chemokine production and consequently contributes to the development and progression of many diseases, such as autoimmune diseases including lupus erythematous and rheumatoid arthritis, cancer, sepsis, Alzheimer’s disease, and diabetes type 1.