RESUMO
Infection with Chlamydia pneumoniae (Cp) accounts for around 10% of community acquired bacterial pneumonia and has been associated with other chronic inflammatory conditions. We describe a C57/Bl6 murine model of Cp lung infection characterized by a dose-dependent, resolving neutrophilia followed by lymphocytic infiltration of the lungs. By 21 days post-infection, mice exhibit a T helper type 1 (Th1) polarized serum antibody response with local mucosal antibody secretion and organization of ectopic lymphoid tissue which persisted in the absence of detectable Cp DNA. Macrophage inflammatory protein (MIP)-2/CXCL2, which recruits neutrophils and lymphocytes and is associated with ectopic lymphoid tissue formation, was secreted in the lungs post-infection. In vitro, lung epithelial cells up-regulated MIP-2/CXCL2 in response to both rough lipopolysaccharide (reLPS) and Cp infection. We conclude that Cp infection can have long-term inflammatory effects on tissue that persist after clearance of active infection.
Assuntos
Quimiocina CXCL2/metabolismo , Infecções por Chlamydophila/patologia , Chlamydophila pneumoniae , Coristoma/patologia , Pulmão/patologia , Tecido Linfoide/patologia , Mucosa Respiratória/metabolismo , Animais , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/citologia , Líquido da Lavagem Broncoalveolar/imunologia , Linhagem Celular , Quimiocina CXCL2/genética , Infecções por Chlamydophila/metabolismo , Infecções por Chlamydophila/microbiologia , Coristoma/imunologia , DNA Bacteriano/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Imunoglobulina A/imunologia , Imunoglobulina A/metabolismo , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Inflamação/patologia , Lipopolissacarídeos/imunologia , Lipopolissacarídeos/farmacologia , Pulmão/metabolismo , Pulmão/microbiologia , Linfócitos/patologia , Tecido Linfoide/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/patologia , Mucosa Respiratória/patologia , Fatores de TempoRESUMO
Ovine chlamydial abortion is a serious cause of fetal mortality in several sheep-rearing countries. The causal agent, Chlamydophila abortus (Chlamydia psittaci), does not generally induce clinical signs in the ewe other than abortion; this is associated with macroscopically visible damage in the placenta, which may be inflamed and thickened. To investigate the nature of the placental inflammation, seven pregnant sheep were inoculated subcutaneously at 70 days' gestation with C. abortus (strain S 26/3). A further five pregnant sheep received control inoculum by the same route at the same stage of pregnancy. Three of the infected ewes produced stillborn lambs and four produced live lambs. Lesions characteristic of chlamydial infection were present in all placentas except for two from one ewe that gave birth to twins. Histopathological examination of placental tissues from aborted fetuses showed a mixed inflammatory cell infiltrate with vasculitis and thrombosis in the mesenchyme of the intercotyledonary membranes. Cells expressing the macrophage-associated molecule CD 14 were found to be numerous, as were cells expressing major histocompatibility complex class II (MHC II) molecules. Many cells expressing messenger RNA (mRNA) encoding for tumour necrosis factor-alpha (TNF-alpha) were demonstrated, but few cells expressing interferon gamma mRNA and none expressing interleukin-4 mRNA were detected. The fetal immune response included small numbers of CD4+ and CD8+ cells, gamma delta T cells and B cells. It is concluded that abortion is the result of several factors, including destruction of tissue by C. abortus, vascular thrombosis, and an inflammatory response by the fetus. Production of TNF-alpha by fetal macrophages expressing MHC II molecules may be of considerable significance in the pathogenesis of abortion.
Assuntos
Aborto Animal/patologia , Chlamydophila psittaci/patogenicidade , Placenta/patologia , Doenças dos Ovinos/patologia , Aborto Animal/etiologia , Aborto Animal/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Chlamydophila psittaci/fisiologia , Modelos Animais de Doenças , Feminino , Morte Fetal/etiologia , Morte Fetal/imunologia , Morte Fetal/patologia , Morte Fetal/veterinária , Idade Gestacional , Antígenos de Histocompatibilidade Classe II/metabolismo , Imunofenotipagem/veterinária , Hibridização In Situ/veterinária , Interferon gama/genética , Interferon gama/metabolismo , Receptores de Lipopolissacarídeos/metabolismo , Placenta/imunologia , Placenta/metabolismo , Gravidez , RNA Mensageiro/metabolismo , Ovinos , Doenças dos Ovinos/imunologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The genomes of Chlamydia spp. encode a family of putative outer membrane proteins, referred to as polymorphic outer membrane proteins (POMPs), which may play a role in the avoidance of host immune defenses. We analyzed avian strain 6BC of Chlamydia psittaci by polyacrylamide gel electrophoresis for the expression of POMPs. At least six putative POMPs were identified on the basis of their size (90 to 110 kDa) and labeling with an outer membrane-specific probe, 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine. Three of the putative POMPs reacted with antiserum raised against a recombinant ovine C. psittaci strain POMP, and two possessed surface-exposed, trypsin-sensitive sites. The POMPs were dependent on disulfide bonds for their maintenance in sodium lauryl sarcosine- and sodium dodecyl sulfate-insoluble complexes but did not appear to be interpeptide disulfide bond cross-linked. The putative POMPs were found to be synthesized during the late phase of the chlamydial developmental cycle, cotemporally with the cysteine-rich doublet periplasmic proteins.
Assuntos
Proteínas da Membrana Bacteriana Externa/análise , Chlamydophila psittaci/química , Proteínas da Membrana Bacteriana Externa/química , Proteínas da Membrana Bacteriana Externa/genética , Dissulfetos/química , Peso MolecularRESUMO
A cDNA was isolated from an adult Haemonchus contortus cDNA expression library the deduced amino acid sequence of which showed significant homology to mammalian pepsinogen sequences. The library was screened with antisera raised against Haemonchus galactose-containing glycoprotein complex, a gut membrane protein complex with aspartyl proteinase activity which has shown considerable potential as a protective antigen. The amino acid sequence obtained corresponded very closely in part to the N-terminal amino acid sequences of two polypetides within the complex. The enzyme was shown to be almost exclusively expressed by the blood-feeding parasite stages. The cDNA was expressed in E. coli, and antibody produced to the recombinant protein bound to the luminal surface of the gut in the adult parasite. The proteinase may play a central role in digesting the blood meal and is considered a potential sub-unit vaccine candidate.
Assuntos
Ácido Aspártico Endopeptidases/genética , Haemonchus/enzimologia , Haemonchus/genética , Sequência de Aminoácidos , Animais , Anticorpos Anti-Helmínticos , Ácido Aspártico Endopeptidases/imunologia , Clonagem Molecular , DNA Complementar/genética , DNA de Helmintos/genética , Escherichia coli/genética , Haemonchus/crescimento & desenvolvimento , Proteínas de Helminto/genética , Proteínas de Helminto/imunologia , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/imunologia , Dados de Sequência Molecular , Pepsinogênios/genética , Homologia de Sequência de AminoácidosRESUMO
The calcium-binding proteins calgranulins A and B co-purified with an elastase-specific inhibitor after the affinity and cation-exchange chromatography of the perchloric acid-soluble fraction of pooled sputum collected from patients with chronic obstructive pulmonary disease (Sallenave, J.-M. and Ryle, A.P. (1991) Biol. Chem. Hoppe-Seyler 372, 13-21). The calgranulins were separated from the inhibitor by reverse-phase FPLC. Protein blot analysis of the calgranulin fraction in the absence of reducing agent revealed a band of 25 kDa corresponding to the disulphide-bonded heterodimerization of the two monomer components. Similar results were obtained from the immunoprecipitation and protein blot analysis of plasma, granulocytes and cultured epithelial cells. This implies that the calgranulins exist in the heterodimeric form in secretions in vivo. Their association with pancreatic elastase during the affinity chromatography stage of purification implicates them in the tissue destruction elicited by the inflammatory response in chronic obstructive pulmonary diseases.
Assuntos
Proteínas de Ligação ao Cálcio/química , Epitélio/química , Granulócitos/química , Escarro/química , Cálcio/química , Proteínas de Ligação ao Cálcio/sangue , Calgranulina A , Calgranulina B , Células Cultivadas , Fibrose Cística/fisiopatologia , Humanos , Substâncias Macromoleculares , Peso Molecular , Testes de PrecipitinaRESUMO
Antipsychotic drugs of known antidiarrhoeal and anticalmodulin activity inhibited the cholera-toxin-catalysed ADP-ribosylation of proteins of Mr 37,000, 40,000 and 45,000 (thought to be regulatory components of the adenylate cyclase complex) that was previously shown to occur in plasma membranes from rabbit intestinal epithelial cells [(1989) Biochim. Biophys. Acta 1014, 289-297]. There was no obvious correlation between the different activities of the drugs. The drugs also inhibited adenylate cyclase activity, but in this case the inhibition correlated well with the known IC50 values of the drugs for anticalmodulin activity and with their antidiarrhoeal activities.