title: The Spr1875 protein confers resistance to the microglia-mediated killing of Streptococcus pneumoniae.
abstract: By screening a whole-genome λ-display library of Streptococcus pneumoniae, we have previously identified a novel surface protein, named Spr1875, that exhibited immunogenic properties and was closely related to pneumococcal virulence. In the present study, we investigated the role of the Spr1875 antigen in the interaction of S. pneumoniae with microglia, the resident brain macrophages. By using an in vitro infection model, the BV2 microglial cell line was challenged with the S. pneumoniae strain DP1004 and its isogenic spr1875-deleted mutant (Δspr1875). Both strains were phagocytosed by microglia efficiently and to a similar extent; however, the DP1004 strain was more resistant than the Δspr1875 mutant to the intracellular killing, as assessed by antibiotic protection and phagosome maturation assays. Moreover, significant differences between the two strains were also observed in terms of susceptibility to microglia-mediated killing. Taken together, these results indicate that S. pneumoniae-microglial cell interplay is influenced by the presence of Spr1875, suggesting that this protein may play a role in the pathogenesis of pneumococcal meningitis.
authors.affiliation: Dipartimento di Medicina Diagnostica, Clinica e di Sanità Pubblica, Università di Modena e Reggio Emilia (Unimore), 41125 Modena, Italy. samuele.peppoloni@unimore.it
authors.forename: Samuele
authors.initials: S
authors.lastname: Peppoloni
authors.forename: Bruna
authors.initials: B
authors.lastname: Colombari
authors.forename: Concetta
authors.initials: C
authors.lastname: Beninati
authors.forename: Franco
authors.initials: F
authors.lastname: Felici
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Teti
authors.forename: Pietro
authors.initials: P
authors.lastname: Speziale
authors.forename: Susanna
authors.initials: S
authors.lastname: Ricci
authors.forename: Andrea
authors.initials: A
authors.lastname: Ardizzoni
authors.forename: Lidia
authors.initials: L
authors.lastname: Manca
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Blasi
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D017353:Gene Deletion; D054884:Host-Pathogen Interactions; D006801:Humans; D050296:Microbial Viability; D017628:Microglia / Q000276:immunology* / Q000382:microbiology*; D010587:Phagocytosis; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity*; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors