title: LMOh7858_0369, a gene encoding a putative leucine-rich repeat-containing protein, is required for virulence of Listeria monocytogenes.
abstract: Listeria monocytogenes possesses the highest number of leucine-rich repeat (LRR)-containing proteins among all Gram-positive bacteria; these LRR-containing molecules are known as the 'internalin' family. To understand the functions of largely uncharacterized LRR-containing molecules, we constructed seven deletion mutants in the L. monocytogenes H7858 strain targeting genes in this family and tested their virulence. Among the seven mutants, the ΔLMOh7858_0369 strain and the ΔLMOh7858_2546 strain showed significantly impaired invasiveness of HepG2 cells. We further tested the virulence of these two strains in the intravascular sepsis model using BALB/c mice. Interestingly, the ΔLMOh7858_0369 strain showed significant reduction in organ colonization, bacteremia and invasion of the brain compared with the parental wild-type strain. Host immune responses to listerial intravascular infection were measured at 24 and 72 h post-infection. Transcript levels of several proinflammatory cytokines and chemokines were significantly lower when induced by the ΔlmOh7858_0369 strain than when induced by the wild type. These results suggest that the putative LRR-containing protein encoded by LMOh7858_0369 might be a novel virulence factor of the L. monocytogenes H7858 strain.
authors.affiliation: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, MS, USA.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, MS, USA.
authors.forename: Dongryeoul
authors.initials: D
authors.lastname: Bae
authors.affiliation: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, MS, USA cw57@msstate.edu.
authors.forename: Chinling
authors.initials: C
authors.lastname: Wang
mesh_terms: D000818:Animals; D001921:Brain / Q000382:microbiology; D018925:Chemokines / Q000235:genetics; D016207:Cytokines / Q000235:genetics; D017353:Gene Deletion; D056945:Hep G2 Cells; D006801:Humans; D000090263:Leucine-Rich Repeat Proteins; D008089:Listeria monocytogenes / Q000235:genetics* / Q000472:pathogenicity*; D008088:Listeriosis / Q000276:immunology / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D018805:Sepsis / Q000382:microbiology; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D018925:Chemokines; D016207:Cytokines; D000090263:Leucine-Rich Repeat Proteins; D011506:Proteins; D037521:Virulence Factors
keywords: LRR; Leucine-rich repeats; Listeria monocytogenes; virulence