Toll-like receptor 2 on inflammatory monocytes induces type I interferon in response to viral but not bacterial ligands

Bacterial ligands cannot induce Toll-like receptor 2 (TLR2)-dependent production of type I interferon. Barton and colleagues find that, in contrast, viral ligands trigger TLR2-dependent interferon production by a subset of inflammatory monocytes. Despite the paradigm that the innate immune system uses nucleic acid–specific receptors to detect viruses because of a lack of other conserved features, many viruses are recognized by Toll-like receptor...