Toll - Like Receptor 2 (TLR2) is a transmembrane protein that plays a crucial role in the innate immune system. It is expressed on the surface of various immune cells, such as macrophages and dendritic cells. TLR2 recognizes a wide range of pathogen - associated molecular patterns (PAMPs), including lipopeptides, peptidoglycans, and lipoteichoic acid from bacteria, as well as components from fungi and viruses. Upon ligand binding, TLR2 initiates a signaling cascade that leads to the activation of transcription factors, such as NF - κB, resulting in the production of pro - inflammatory cytokines and chemokines, which help recruit immune cells to the site of infection and initiate an immune response.TLR2 can form a heterodimer with TLR1, which enhances the recognition of specific PAMPs, expands the range of detectable pathogens, and improves the accuracy and efficiency of the immune response.Thus a functional ELISA assay was conducted to detect the interaction of recombinant human TLR2 and recombinant human TLR1. Briefly, TLR2 was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to TLR1-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-TLR2 pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody for 1h at 37℃, wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50 µL stop solution to the wells and read at 450/630nm immediately. The binding activity of recombinant human TLR2 and recombinant human TLR1 was shown in Figure 1, the EC50 for this effect is 0.09 μg/mL.