title: Macrophages recognize streptococci through bacterial single-stranded RNA.
abstract: Group B streptococcus (GBS) is a leading cause of both neonatal sepsis and meningitis, two diseases that are characterized by inflammation. However, the manner in which GBS organisms are recognized by monocytes and macrophages is poorly understood. In this study, we report that the recognition of GBS and other Gram-positive bacteria by macrophages and monocytes relies on bacterial single-stranded RNA (ssRNA). ssRNA interacts with a signalling complex, which comprises the Toll-like receptor adaptors MyD88 and UNC-93B, but not the established MyD88-dependent ssRNA sensors. The role of ssRNA in the recognition of Gram-positive bacteria--leading to the induction of inflammatory cytokines--has potential implications for sepsis pathogenesis, diagnosis and treatment.
authors.affiliation: Centre of Chronic Immunodeficiency, Medical Centre, University Freiburg, Breisacherstrasse 117, Freiburg 79106, Germany.
authors.forename: Sachin D
authors.initials: SD
authors.lastname: Deshmukh
authors.forename: Bernhard
authors.initials: B
authors.lastname: Kremer
authors.forename: Marina
authors.initials: M
authors.lastname: Freudenberg
authors.forename: Stefan
authors.initials: S
authors.lastname: Bauer
authors.forename: Douglas T
authors.initials: DT
authors.lastname: Golenbock
authors.forename: Philipp
authors.initials: P
authors.lastname: Henneke
mesh_terms: D000818:Animals; D001483:Base Sequence; D016207:Cytokines / Q000096:biosynthesis; D054884:Host-Pathogen Interactions; D006801:Humans; D007231:Infant, Newborn; D008264:Macrophages / Q000276:immunology / Q000382:microbiology*; D026901:Membrane Transport Proteins / Q000276:immunology; D051379:Mice; D008969:Molecular Sequence Data; D053594:Myeloid Differentiation Factor 88 / Q000276:immunology; D012329:RNA, Bacterial / Q000276:immunology / Q000502:physiology*; D013292:Streptococcus agalactiae / Q000502:physiology*
chemical_list: D016207:Cytokines; D026901:Membrane Transport Proteins; D053594:Myeloid Differentiation Factor 88; D012329:RNA, Bacterial; C512254:UNC93B1 protein, mouse