<p>A prolonged exposure of reducing sugar to protein leads to a non-enzymatic reaction called the Maillard reaction and results in the production of advanced glycation end products (AGEs). AGEs consist of heterogeneous compounds, and AGEs are produced by the reaction of proteins with various types of reacting carbonyl compound. We have previously demonstrated that a glycolaldehyde-derived AGE (AGE3) suppresses stimulator of interferon gene (STING)/TANK-binding kinase 1 (TBK1)/interferon regulatory transcription factor 3 (IRF3), which is a component of the innate immune system. In the present study, we investigated the effects of AGEs prepared by several carbonyl compounds on STING/TBK1/IRF3 signaling. AGEs used in the present study were numbered based on the carbonyl compound type: AGE1, derived from glucose; AGE2, derived from glyceraldehyde; AGE3, derived from glycolaldehyde; AGE4, derived from methylglyoxal; and AGE5, derived from glyoxal.</p><p>AGEs derived from aldehyde (AGE2 and AGE3) and dicarbonyl compounds (AGE4 and AGE5) suppressed cyclic GMP-AMP (cGAMP)-induced activation of STING/TBK1/IRF3 signaling, with different suppression efficiencies observed. Among the AGEs used, only AGE1 enhanced cGAMP-induced activation of STING/TBK1/IRF3 signaling. Enhancing the modulation of STING/TBK1/IRF3 signaling by AGE1 was mediated by toll-like receptor 4.</p><p>These results indicated that modulation of STING/TBK1/IRF3 signaling by prepared AGEs is dependent on the type and concentration of the carbonyl compound present.</p>