Toll – like receptors (TLRs) are germline encoded single pass Transmembrane receptors of the innate immune system, conserved from Drosophila to mammals. They are members of the family of PRRs (Pattern Recognition Receptors) involved informing the first line of defense against detection of microbes upon infection. TLRs recognize specific pathogens or Pathogen – Associated Molecular Patterns (PAMPs) and trigger signaling cascades leading to host immune responses and inflammation.

Source: Cell Biology Vol – 27, No-1, January 2007.