title: Differential role of lipooligosaccharide of Neisseria meningitidis in virulence and inflammatory response during respiratory infection in mice.
abstract: Meningococcal lipooligosaccharide (LOS) induces a strong proinflammatory response in humans during meningococcal infection. We analyzed the role of LOS in the inflammatory response and virulence during the early infectious process in a mouse model of meningococcal respiratory challenge. An lpxA mutant strain (serogroup B) devoid of LOS (strain Z0204) could not persist in the lungs and did not invade the blood. The persistence in the lungs and invasion of the bloodstream by a rfaD mutant expressing truncated LOS with only lipid A and 3-deoxy-d-manno-2-octulosonic acid molecules (strain Z0401) was intermediate between those of the wild-type and Z0204 strains. Both LOS mutants induced acute pneumonia with the presence of infiltrating polymorphonuclear leukocytes in lungs. Although tumor necrosis factor alpha production was reduced in mice infected with the mutant of devoid LOS, both LOS mutants induced production of other proinflammatory cytokines, such as interleukin-1beta (IL-1beta), IL-6, and the murine IL-8 homolog KC. Together, these results suggest that meningococcal LOS plays a role during the early infectious and invasive process, and they further confirm that other, nonlipopolysaccharide components of Neisseria meningitidis may significantly contribute to the inflammatory reaction of the host.
authors.affiliation: Unité des Neisseria, Institut Pasteur, 25-28 rue du Dr Roux, 75724 Paris Cedex 15, France. lzaranto@pasteur.fr
authors.forename: Maria Leticia
authors.initials: ML
authors.lastname: Zarantonelli
authors.forename: Michel
authors.initials: M
authors.lastname: Huerre
authors.forename: Muhamed-Kheir
authors.initials: MK
authors.lastname: Taha
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Alonso
mesh_terms: D000818:Animals; D018925:Chemokines / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D005260:Female; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000276:immunology*; D008168:Lung / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D008589:Meningococcal Infections / Q000276:immunology* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D009345:Neisseria meningitidis / Q000235:genetics / Q000472:pathogenicity*; D018410:Pneumonia, Bacterial / Q000276:immunology* / Q000473:pathology; D012141:Respiratory Tract Infections / Q000276:immunology / Q000473:pathology; D014774:Virulence / Q000235:genetics / Q000276:immunology; D037521:Virulence Factors / Q000235:genetics / Q000276:immunology*
chemical_list: D018925:Chemokines; D016207:Cytokines; D053583:Interleukin-1beta; D015850:Interleukin-6; D016209:Interleukin-8; D008070:Lipopolysaccharides; D037521:Virulence Factors; C023023:lipid-linked oligosaccharides