| 1. |
- Baker, N, et al.
(författare)
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Glycosphingolipid receptors for Pseudomonas aeruginosa.
- 1990
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Ingår i: Infection and immunity. - 0019-9567. ; 58:7, s. 2361-6
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Tidskriftsartikel (refereegranskat)abstract
- The binding of Pseudomonas aeruginosa to glycosphingolipids and to buccal and bronchial epithelial cells was analyzed. Three independently expressed specificities were found by bacterial binding to glycosphingolipids separated by thin-layer chromatography. All strains bound gangliotria- and gangliotetrasylceramide. All but one of the strains bound sialic acid-containing glycosphingolipids and lactosylceramide. The latter two specificities could be separated in that the lactosylceramide binding was retained and the sialic acid binding was suppressed when bovine serum albumin was used as a blocking agent in the thin-layer chromatography assay. The attachment to buccal epithelial cells, like the binding to sialylated compounds and lactosylceramide, was abolished by Formalin treatment of the bacteria, suggesting the importance of these specificities for cell adherence. In contrast, the binding to gangliotria- and gangliotetraosylceramide was retained by nonattaching Formalin-treated bacteria.
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| 2. |
- Hedges, S., et al.
(författare)
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Uroepithelial cells are part of a mucosal cytokine network
- 1994
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Ingår i: Infection and Immunity. - 0019-9567. ; 62:6, s. 2315-2321
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Tidskriftsartikel (refereegranskat)abstract
- This study compared the cytokine production of uroepithelial cell lines in response to gram-negative bacteria and inflammatory cytokines. Human kidney (A498) and bladder (J82) epithelial cell lines were stimulated with either Escherichia coli Hu734, interleukin 1α (IL-1α), or tumor necrosis factor alpha (TNF-α). Supernatant samples were removed, and the RNA was extracted from cells at 0, 2, 6, and 24 h. The secreted cytokine levels were determined by bioassay or immunoassay; mRNA was examined by reverse transcription-PCR. The two cell lines secreted IL-6 and IL-8 constitutively. IL-6 and IL-8 mRNA were constitutively produced in both cell lines; IL-1β mRNA was detected in J82 cells. IL-1α induced significantly higher levels of IL-6 secretion than did E. coli Hu734 or TNF-α. IL-1α and TNF-α induced significantly higher levels of IL-8 secretion than did E. coli Hu734. Secreted IL-1β was not detected; IL-1α and TNF-α were not detected above the levels used for stimulation. IL-1α, IL-1β, IL-6, and IL-8 mRNAs were detected in both cell lines after exposure to the stimulants. TNF-α mRNA was occasionally detected in the J82 cell line after TNF-α stimulation. Cytokine (IL-6 and IL-8) and control (glyceraldehyde 3-phosphate dehydrogenase [G3PDH] and β-actin) mRNA concentrations were quantitated with internal PCR standards. Cytokine mRNA levels relative to β-actin mRNA levels were the highest in E. coli- stimulated cells. In comparison, the cytokine mRNA levels relative to G3PDH mRNA levels were the highest in IL-1α-stimulated cells. β-Actin mRNA levels decreased after bacterial stimulation but not after cytokine stimulation, while G3PDH mRNA levels increased in response to all of the stimulants tested. These results suggested that E. coli Hu734 lowered the β-actin mRNA levels in uroepithelial cells, thus distorting the IL-6 and IL-8 mRNA levels relative to this control. In summary, E. coli IL-1α and TNF-α were found to activate the de novo synthesis and secretion of IL-6 and IL-8 in uroepithelial cells. These results emphasize the role of epithelial cells in cytokine-mediated responses during the early stages of infection.
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| 3. |
- Wold, Agnes E, 1955, et al.
(författare)
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Lectin receptors on IgA isotypes.
- 1994
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Ingår i: Scandinavian journal of immunology. - 0300-9475. ; 39:2, s. 195-201
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Tidskriftsartikel (refereegranskat)abstract
- It has been shown previously that secretory IgA interacts with the mannose-specific lectin of Escherichia coli. The purpose of the study described here was to evaluate whether the N-linked oligosaccharide chains of the human IgA isotypes IgA1 and IgA2 differ in lectin receptor activity. A range of plant lectins specific for N-linked oligosaccharide chains were tested for their ability to precipitate IgA1 and IgA2 myeloma proteins, secretory IgA and free secretory component. IgA2 myeloma proteins reacted more strongly than IgA1 with the mannose-specific lectin ConA, whereas IgA1 myeloma proteins reacted more strongly than IgA2 with two galactose-specific lectins, Ricinus communis agglutinin I and Abrus precatorius agglutinin. This suggests that IgA2 possesses a larger proportion of short truncated complex type oligosaccharide chains and/or oligomannose type chains than IgA1. Further, IgA2 reacted more strongly than IgA1 myeloma proteins with Lens culinaris (lentil) lectin, and Pisum sativum (pea) lectin, suggesting that IgA2 exposes more of short, complex type chains fucosylated on the core than IgA1. The differences demonstrated in receptor activity between IgA1 and IgA2 may be important in their interaction with the microbial flora, as well with endogenous lectins, such as phagocyte receptors.
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| 4. |
- Agace, W., et al.
(författare)
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Selective cytokine production by epithelial cells following exposure to Escherichia coli
- 1993
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Ingår i: Infection and Immunity. - 0019-9567. ; 61:2, s. 602-609
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Tidskriftsartikel (refereegranskat)abstract
- This study compared the repertoire of cytokines produced by epithelial cell lines and human peripheral blood monocytes in response to Escherichia coli. The A-498 and J82 urinary tract epithelial cell lines and human peripheral blood monocytes were exposed to E. coli Hu734. The cytokine content of single cells was detected by indirect immunofluorescence using monoclonal antibodies to interleukin-1α (IL-1α), IL-1β, tumor necrosis factor alpha (TNF-α), TNF-β, IL-6, IL-8, and granulocyte macrophage- colony-stimulating factor, and the number of positive cells was used to quantitate the response. The J82 bladder cell line stained positive for IL- 6, IL-8, and IL-1α. The IL-8 and IL-6 response peaked at 2 h, while the number of IL-1α-positive cells reached a peak 6 h after E. coli stimulation. The A-498 kidney cell line stained for IL-8 with a peak at 2 h and IL-6 with a peak at 6 h after E. coli stimulation. Peripheral blood monocytes stained for the cytokines IL-1α, IL-1β, IL-8, IL-6, and TNF-α but not for TNF-β and granulocyte macrophage-colony-stimulating factor after stimulation with E. coli. The results demonstrated that bacteria activated a cytokine response in the epithelial cell lines and monocytes. The epithelial cell lines had a more limited cytokine response profile than circulating monocytes, which may serve to limit the consequences of microbial exposure at the mucosal surface and help maintain the integrity of other tissue compartments.
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| 5. |
- Agace, W. W., et al.
(författare)
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Interleukin-8 and the neutrophil response to mucosal gram-negative infection
- 1993
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Ingår i: Journal of Clinical Investigation. - 0021-9738. ; 92:2, s. 780-785
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Tidskriftsartikel (refereegranskat)abstract
- Urinary tract infections activate a mucosal inflammatory response, which includes cytokine secretion and neutrophil influx. The mechanisms involved in the neutrophil influx have not been identified. Interleukin-8, a potent chemoattractant for neutrophils, is produced by urinary tract epithelial cell lines in vitro. This study analyzed the human IL-8 response to deliberate Escherichia coli infection of the urinary tract. Urine and serum samples were obtained before and after intravesical instillation of E. coli. Neutrophil numbers were determined on uncentrifuged urine, and IL-8 levels were measured by ELISA. A urinary IL-8 response was found in all patients after bacterial instillation, but no serum IL-8 was detected. There was a strong correlation between urinary IL-8 levels and urinary neutrophil numbers. The same E. coli strains used to colonize the patients stimulated IL-8 production in urinary tract epithelial cells. The level of IL-8 secreted by epithelial cell lines was influenced by the fimbrial properties of the E. coli. These results demonstrated that E. coli elicit a mucosal IL-8 response in humans, and suggested that IL-8 is involved in the onset of pyuria. Epithelial cells may be an important source of IL-8 during urinary tract infection.
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| 6. |
- HEDGES, S., et al.
(författare)
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Cyclosporin A does not Inhibit IL‐lα‐Induced Epithelial Cell IL‐6 Secretion
- 1993
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 37:5, s. 581-586
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Tidskriftsartikel (refereegranskat)abstract
- Trauma and infection activated a murine mucosal IL‐6 response in different ways: the IL‐6 response to bacteria was sensitive to Cyclosporin A (CsA); the IL‐6 response to trauma was not. The aim of the present study was to identify possible activators of the CsA‐insensitive IL‐6 secretion at the epithelial cell level. Two human epithelial cell lines from the kidney (A498) and bladder (J82) were exposed to Escherichia coli Hu734, interleukin‐lα (IL‐lα) and tumour necrosis factor a (TNF‐α). The E. coli strain had been used for the in vivo experiments which led to this study, and IL‐lα and TNF‐α were likely to be released during infections and trauma. The secretion of IL‐6 into the supernatants was compared between cells stimulated in the presence or absence of CsA. E. coli Hu734, IL‐lα and TNF‐α stimulated an IL‐6 response in the two epithelial cell lines. The IL‐lα‐induced IL‐6 response was rapid, and the secreted IL‐6 levels were significantly higher than those induced by E. coli Hu734 or TNF‐α. The IL‐6 response to IL‐ lα was insensitive to CsA. By contrast, the IL‐6 response to E. coli Hu734 and TNF‐α was inhibited by CsA. These results demonstrated that the inhibitory effect of CsA depends on the stimulus triggering the IL‐6 response. IL‐lα may play a role in the induction of trauma‐associated CsA‐insensitive IL‐6 secretion.
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| 7. |
- Johanson, I M, et al.
(författare)
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Pap, papG and prsG DNA sequences in Escherichia coli from the fecal flora and the urinary tract.
- 1993
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Ingår i: Microbial pathogenesis. - : Elsevier BV. - 0882-4010. ; 15:2, s. 121-9
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Tidskriftsartikel (refereegranskat)abstract
- The pap gene clusters encode P fimbriae and fimbriae-associated G adhesins. DNA sequence analysis has resolved three G adhesin variants (papGJ96, papGIA2 and prsGJ96) that differ in receptor specificity and therefore in binding to epithelial cells. In this study, DNA probes specific for the pap gene cluster or the papGJ96, papGIA2 and prsGJ96 adhesin sequences were used to examine 74 fecal and 204 urinary Escherichia coli isolates (67 from acute pyelonephritis, 71 from acute cystitis and 66 from asymptomatic bacteriuria). In accordance with previous studies, a higher frequency of pap+ strains was found in the urinary strains (71%) than in the fecal (20%) E. coli isolates. The papGIA2, and prsGJ96 sequences were more frequent among urinary (42% papG+IA2, 23% prsG+J96) than among fecal (18% papG+IA2, 5% prsG+J96) isolates. None of the isolates hybridized with the papGJ96 probe. Pap+ strains accounted for 82% of the pyelonephritis, 69% of the cystitis and 61% of the asymptomatic bacteriuria strains. The papGIA2 genotype dominated in acute pyelonephritis strains (72% papG+IA2, 16% prsG+J96). The prsGJ96 genotype was most frequent in cystitis strains (25% papG+IA2, 37% prsG+J96). The asymptomatic bacteriuria strains formed an intermediate group (30% papG+IA2, 14% prsG+J96). Most of the papG+IA2 strains expressed P fimbriae which agglutinated human erythrocytes, sheep erythrocytes and Gal alpha 1-4Gal beta latex beads. The prsG+J96 strains varied in agglutination of human and sheep erythrocytes and Gal alpha 1-4Gal beta-latex beads. The results demonstrated that the papGIA2 and prsGJ96 adhesin DNA sequences differ in disease association.
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| 8. |
- Lodinová-Zádníková, R, et al.
(författare)
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The antibody response in breast-fed and non-breast-fed infants after artificial colonization of the intestine with Escherichia coli O83.
- 1991
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Ingår i: Pediatric research. - : Springer Science and Business Media LLC. - 0031-3998 .- 1530-0447. ; 29:4 Pt 1, s. 396-9
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Tidskriftsartikel (refereegranskat)abstract
- The local and systemic antibody response after oral administration of a nonenteropathogenic type 1 fimbriated Escherichia coli O83 strain was followed in nine breast-fed and eight formula-fed infants during their first 15 wk of life. Five breast-fed and six formula-fed infants were followed as controls. E. coli O83 was detected in the stools of colonized infants from d 2 after colonization and persisted in the intestine for up to 26 wk. The percentage of children successfully colonized with E. coli O83 was higher among breast-fed than among formula-fed colonized infants. Also, the O83 bacteria isolated from the breast-fed children had a higher capacity to attach to colonic epithelial cells of the HT-29 cell line than those isolated from bottle-fed infants. E. coli O83 IgA and IgM antibodies estimated by ELISA were significantly elevated in the saliva of colonized as compared with control infants 2-7 wk after colonization. IgA antibodies against O83 were also higher in the stool of colonized formula-fed infants than in formula-fed controls. The results suggest that the mucosal immune system of the newborn infant can be triggered early to produce specific antibodies against bacteria colonizing the intestine.
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| 9. |
- Otto, Gisela, et al.
(författare)
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Virulence factors and pap genotype in Escherichia coli isolates from women with acute pyelonephritis, with or without bacteremia.
- 1993
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Ingår i: Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. - 1058-4838. ; 17:3, s. 448-56
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Tidskriftsartikel (refereegranskat)abstract
- Bacteremia develops in a subgroup of patients with acute pyelonephritis. This study examined isolates of Escherichia coli from the urine and the blood of 25 bacteremic and 67 nonbacteremic women with this acute disease. P-fimbriated strains were found in 100% of bacteremic patients without complicating factors but in only 71% of nonbacteremic patients without complications (P < .05). Non-P-fimbriated strains were only found to cause bacteremia in three patients with compromising host factors. Strains from the bacteremic group and those from the nonbacteremic group did not differ significantly in terms of hemolysin or aerobactin production or of serum resistance. The P-fimbriated strains from both groups of patients carried pap DNA sequences of the papGIA2 adhesin type; prsGJ96 homologous DNA sequences were rare. The results suggested that P fimbriae and compromising host conditions independently increase the risk for bacteremia during acute pyelonephritis.
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| 10. |
- Plos, Kaety, 1944, et al.
(författare)
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Escherichia coli in patients with renal scarring: genotype and phenotype of Gal alpha 1-4Gal beta-, Forssman- and mannose-specific adhesins.
- 1991
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Ingår i: The Pediatric infectious disease journal. - 0891-3668. ; 10:1, s. 15-9
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Tidskriftsartikel (refereegranskat)abstract
- The frequency of Escherichia coli with Gal alpha 1-4Gal beta-specific adhesins is reduced among children who develop renal scars. The adhesion-negative phenotype may be due to the absence of the pap DNA sequences which encode these adhesins or to a phase variation event induced by in vitro culture. In the present study the frequency of pap and pil homologous DNA was determined by dot blot analysis with probes specific for the respective sequence using E. coli strains from children with recurrent pyelonephritis with and without renal scarring. The frequency of pap was 79% in the strains isolated from the nonscarring group compared with 39% in the strains from the scarring group (P less than 0.001). The Gal alpha 1-4Gal beta phenotype was expressed by 89% of the pap-positive strains from the nonscarring group compared with 71% in the scarring group (P less than 0.05). In addition 13 of 77 of the pap-positive E. coli strains agglutinated sheep erythrocytes but not the Gal alpha 1-4Gal beta latex beads; a reaction attributed to reactivity with the Forssman glycolipid. DNA sequences homologous with pil were found in 95% of all strains and there was no significant difference between the nonscarring and the scarring groups. The low frequency of Gal alpha 1-4Gal beta specific strains in the scarring group was therefore due to the absence of pap-homologous DNA sequences and to a reduced rate of phenotypic expression among pap-positive scarring strains. There was no support for a relationship between type 1 fimbriae and renal scarring.
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