title: TLR9 regulation by proteolysis: a friend or a foe.
abstract: Intracellular TLRs sense viral and bacterial nucleic acids from a wide variety of pathogens. Previous studies have shown that TLR9 requires processing for signalling. Following proteolysis, a fragment corresponding to the C-terminal part of TLR9 was shown to bind MyD88 and to induce signalling when cells were stimulated with TLR9 ligands. In this issue of the European Journal of Immunology, a study provides evidence that another proteolytic fragment of TLR9 is generated, different to that described previously, consisting of amino acids 1-723 which mediates inhibition of TLR9 signalling. These results suggest that proteolysis undoubtedly is a key step in TLR9 regulation.
authors.affiliation: Institut National de la Santé et la Recherche Médicale, Paris, France. benedicte.manoury@inserm.fr
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Manoury
mesh_terms: D000818:Animals; D002403:Cathepsins / Q000378:metabolism*; D011992:Endosomes / Q000378:metabolism*; D006801:Humans; D008954:Models, Biological; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D051217:Toll-Like Receptor 9 / Q000737:chemistry / Q000378:metabolism*
chemical_list: D010446:Peptide Fragments; D051217:Toll-Like Receptor 9; D002403:Cathepsins; C028217:cathepsin S