Toll-like receptor 2: At the intersection of inflammation and immune regulation

Toll-like receptor 2: At the intersection of inflammation and immune regulation

It is necessary for the immune system to be able to differentiate and to respond appropriately to foreign microorganisms within the body, whether they are beneficial or pathogenic. Pattern-recognition receptors (PRRs) are receptors on our immune cells that give the body the ability to recognize and react properly when molecules from bacteria or viruses are present. One class of PRRs are toll-like receptors (TLRs), and humans have 10 known TLRs that help us differentiate between different types of microorganisms. For example, TLR2 recognizes the cell wall of bacteria and yeast, and has two binding partners, TLR1 and TLR6, which releases an inflammatory or an immune suppressing response, respectively, when bound together. Some mutations in these TLRs have shown positive selection during the Black Death in European populations, such as the H34 haplotype. The H34 haplotype is a change in a set of three amino acids in TLR1 and TLR6, one of which shows a decrease inflammatory response from TLR2/1. Our focus is to investigate and better explain the roles of TLR1 and TLR6, as well as their accessory molecules involved in the TLR2 signaling pathway. We also want to analyze the polymorphism H34 haplotype and its effects on immune function in comparison to those without the H34 haplotype. Understanding and answering these questions may give us new targets for immunotherapy, while expanding our knowledge about human health and the immune system.