Current Perspectives of TLR2 Signalling in the Retina

Toll-like receptor 2 (TLR2) signalling is crucial in initiating the innate immune response. Under normal conditions, TLR2 can recognise and respond to danger signals in the body and protect against damaging pathogens and molecules. However, dysregulation of this tightly controlled cascade has been implicated in various retinal disorders. There are many endogenous sterile ligands present in a degenerating retina that could lead to aberrant TLR2 activation. This culminates in an overaction of the innate immune response, which leads to an excess of pro-inflammatory cytokine production and results in a dangerous cycle of chronic inflammation. Here, we will review the evidence behind TLR2's involvement in retinal diseases such as age-related macular degeneration (AMD) and diabetic retinopathy (DR) and investigate the potential therapeutic benefit of TLR2 inhibition in the retina.