| 1. |
- Baker, N, et al.
(author)
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Glycosphingolipid receptors for Pseudomonas aeruginosa.
- 1990
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In: Infection and immunity. - 0019-9567. ; 58:7, s. 2361-6
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Journal article (peer-reviewed)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. |
- Brisuda, Antonín, et al.
(author)
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Bladder cancer therapy using a conformationally fluid tumoricidal peptide complex
- 2021
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12
-
Journal article (peer-reviewed)abstract
- Partially unfolded alpha-lactalbumin forms the oleic acid complex HAMLET, with potent tumoricidal activity. Here we define a peptide-based molecular approach for targeting and killing tumor cells, and evidence of its clinical potential (ClinicalTrials.gov NCT03560479). A 39-residue alpha-helical peptide from alpha-lactalbumin is shown to gain lethality for tumor cells by forming oleic acid complexes (alpha1-oleate). Nuclear magnetic resonance measurements and computational simulations reveal a lipid core surrounded by conformationally fluid, alpha-helical peptide motifs. In a single center, placebo controlled, double blinded Phase I/II interventional clinical trial of non-muscle invasive bladder cancer, all primary end points of safety and efficacy of alpha1-oleate treatment are reached, as evaluated in an interim analysis. Intra-vesical instillations of alpha1-oleate triggers massive shedding of tumor cells and the tumor size is reduced but no drug-related side effects are detected (primary endpoints). Shed cells contain alpha1-oleate, treated tumors show evidence of apoptosis and the expression of cancer-related genes is inhibited (secondary endpoints). The results are especially encouraging for bladder cancer, where therapeutic failures and high recurrence rates create a great, unmet medical need.
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| 3. |
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| 4. |
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| 5. |
- Hedges, S., et al.
(author)
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Uroepithelial cells are part of a mucosal cytokine network
- 1994
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In: Infection and Immunity. - 0019-9567. ; 62:6, s. 2315-2321
-
Journal article (peer-reviewed)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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| 6. |
- Hedman, E., et al.
(author)
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Effectiveness of Internet-based cognitive behaviour therapy for depression in routine psychiatric care
- 2014
-
In: Journal of Affective Disorders. - : Elsevier. - 0165-0327 .- 1573-2517. ; 155:1, s. 49-58
-
Journal article (peer-reviewed)abstract
- Background: Efficacy of guided Internet-based cognitive behaviour therapy (ICBT) for depression has been demonstrated in several randomised controlled trials. Knowledge on the effectiveness of the treatment, i.e. how it works when delivered within routine care, is however scarce. The aim of this study was to investigate the effectiveness of ICBT for depression.Methods: We conducted a cohort study investigating all patients (N =1203) who had received guided ICBT for depression between 2007 and 2013 in a routine care setting at an outpatient psychiatric clinic providing Internet-based treatment The primary outcome measure was the Montgomery Asberg Depression Rating Scale-Self rated (MADRS-S).Results: Patients made large improvements from pre-treatment assessments to post-treatment on the primary outcome (effect size d on the MADRS-S = 1.27, 99% CI, 1.14-1.39). Participants were significantly improved in terms of suicidal ideation and sleep difficulties improvements were sustained at 6-month follow-up.Limitations: Attrition was rather large at 6-month follow-up. However, additional data was collected through telephone interviews with dropouts and advanced statistical models indicated that missing data did not bias the findings.Conclusions: ICBT for depression can be highly effective when delivered within the context of routine psychiatric care. This study suggests that the effect sizes are at least as high when the treatment is delivered in routine psychiatric care by qualified staff as when delivered in a controlled trial setting.
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| 7. |
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| 8. |
- Sheppard, Neil C, et al.
(author)
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Polyethyleneimine is a potent systemic adjuvant for glycoprotein antigens.
- 2014
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In: International Immunology. - : Oxford University Press (OUP). - 1460-2377 .- 0953-8178. ; 26:10, s. 531-538
-
Journal article (peer-reviewed)abstract
- Polyethyleneimine (PEI) is an organic polycation used extensively as a gene- and DNA vaccine delivery reagent. Although the DNA targeting activity of PEI is well documented, its immune activating activity is not. We recently reported that PEI has robust mucosal adjuvanticity when administered intranasally with glycoprotein antigens. Here we show that PEI has strong immune activating activity after systemic delivery. PEI administered subcutaneously with viral glycoprotein (HIV-1 gp140) enhanced antigen-specific serum IgG production in the context of mixed Th1/Th2-type immunity. PEI elicited higher titers of both antigen binding and neutralizing antibodies than alum in mice and rabbits, and induced an increased proportion of antibodies reactive with native antigen. In an intraperitoneal model, PEI recruited neutrophils followed by monocytes to the site of administration, and enhanced antigen uptake by antigen presenting cells. The Th bias was modulated by PEI activation of the Nlrp3 inflammasome, however its global adjuvanticity was unchanged in Nlrp3-deficient mice. When co-formulated with CpG oligodeoxynucleotides, PEI adjuvant potency was synergistically increased and biased towards a Th1-type immune profile. Taken together these data support the use of PEI as a versatile systemic adjuvant platform with particular utility for induction of secondary structure-reactive antibodies against glycoprotein antigens.
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| 9. |
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| 10. |
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| 11. |
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| 12. |
- Wold, Agnes E, 1955, et al.
(author)
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Lectin receptors on IgA isotypes.
- 1994
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In: Scandinavian journal of immunology. - 0300-9475. ; 39:2, s. 195-201
-
Journal article (peer-reviewed)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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| 13. |
- Adlerberth, Ingegerd, 1959, et al.
(author)
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P fimbriae and other adhesins enhance intestinal persistence of Escherichia coli in early infancy.
- 1998
-
In: Epidemiology and infection. - 0950-2688. ; 121:3, s. 599-608
-
Journal article (peer-reviewed)abstract
- Resident and transient Escherichia coli strains were identified in the rectal flora of 22 Pakistani infants followed from birth to 6 months of age. All strains were tested for O-antigen expression, adhesin specificity (P fimbriae, other mannose-resistant adhesins or type 1 fimbriae) and adherence to the colonic cell line HT-29. Resident strains displayed higher mannose-resistant adherence to HT-29 cells, and expressed P fimbriae (P = 0.0036) as well as other mannose-resistant adhesins (P = 0.012) more often than transient strains. In strains acquired during the first month of life, P fimbriae were 12 times more frequent in resident than in transient strains (P = 0.0006). The O-antigen distribution did not differ between resident and transient strains, and none of the resident P-fimbriated strains belonged to previously recognized uropathogenic clones. The results suggest that adhesins mediating adherence to intestinal epithelial cells, especially P fimbriae, enhance the persistence of E. coli in the large intestine of infants.
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| 14. |
- Agace, W., et al.
(author)
-
Selective cytokine production by epithelial cells following exposure to Escherichia coli
- 1993
-
In: Infection and Immunity. - 0019-9567. ; 61:2, s. 602-609
-
Journal article (peer-reviewed)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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| 15. |
- Agace, W. W., et al.
(author)
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Escherichia coli induces transuroepithelial neutrophil migration by an intercellular adhesion molecule-1-dependent mechanism
- 1995
-
In: Infection and Immunity. - 0019-9567. ; 63:10, s. 4054-4062
-
Journal article (peer-reviewed)abstract
- During bacterial infections at mucosal sites, neutrophils migrate to the mucosa and cross the epithelial barrier. We have examined neutrophil migration across Escherichia coli-stimulated uroepithelial cell layers in an attempt to more fully understand this process. Stimulation of uroepithelial cells with E. coli or interleukin-1α (IL-1α) induced transepithelial neutrophil migration in a time- and stimulant dose-dependent manner. Uroepithelial cell lines and nontransformed uroepithelial cells expressed intercellular adhesion molecule-1 (ICAM-1) but not ICAM-2, E-selectin, or P- selectin. Epithelial ICAM-1 expression was enhanced after stimulation with E. coli or IL-1α. Anti-ICAM-1 antibody reduced transepithelial neutrophil migration by 61 to 85%, indicating that neutrophils bound ICAM-1 on the epithelial surface. Antibodies to CD18 and CD11b reduced migration by 70 to 79%, suggesting that CD11b/CD18 (Mac-1) was acting as the neutrophil receptor for ICAM-1 in this process. Anti-CD11a antibodies had no effect on neutrophil migration. In conclusion, E. coli induced ICAM-1- and Mac-1-dependent transepithelial neutrophil migration. Previous studies have shown that urinary tract epithelial cells secrete IL-8 when exposed to E. coli or IL- 1α. These observations suggest that epithelial cells play an active role in neutrophil migration during urinary tract infections.
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| 16. |
- Agace, W. W., et al.
(author)
-
Interleukin-8 and the neutrophil response to mucosal gram-negative infection
- 1993
-
In: Journal of Clinical Investigation. - 0021-9738. ; 92:2, s. 780-785
-
Journal article (peer-reviewed)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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| 17. |
- Ambite, Inès, et al.
(author)
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Active bacterial modification of the host environment through RNA polymerase II inhibition
- 2021
-
In: Journal of Clinical Investigation. - 0021-9738. ; 131:4
-
Journal article (peer-reviewed)abstract
- Unlike pathogens, which attack the host, commensal bacteria create a state of friendly coexistence. Here, we identified a mechanism of bacterial adaptation to the host niche, where they reside. Asymptomatic carrier strains were shown to inhibit RNA polymerase II (Pol II) in host cells by targeting Ser2 phosphorylation, a step required for productive mRNA elongation. Assisted by a rare, spontaneous loss-of-function mutant from a human carrier, the bacterial NlpD protein was identified as a Pol II inhibitor. After internalization by host cells, NlpD was shown to target constituents of the Pol II phosphorylation complex (RPB1 and PAF1C), attenuating host gene expression. Therapeutic efficacy of a recombinant NlpD protein was demonstrated in a urinary tract infection model, by reduced tissue pathology, accelerated bacterial clearance, and attenuated Pol II-dependent gene expression. The findings suggest an intriguing, evolutionarily conserved mechanism for bacterial modulation of host gene expression, with a remarkable therapeutic potential.
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| 18. |
- Ambite, Ines, et al.
(author)
-
Fimbriae reprogram host gene expression - Divergent effects of P and type 1 fimbriae
- 2019
-
In: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 15:6, s. 1007671-1007671
-
Journal article (peer-reviewed)abstract
- Pathogens rely on a complex virulence gene repertoire to successfully attack their hosts. We were therefore surprised to find that a single fimbrial gene reconstitution can return the virulence-attenuated commensal strain Escherichia coli 83972 to virulence, defined by a disease phenotype in human hosts. E. coli 83972pap stably reprogrammed host gene expression, by activating an acute pyelonephritis-associated, IRF7-dependent gene network. The PapG protein was internalized by human kidney cells and served as a transcriptional agonist of IRF-7, IFN-β and MYC, suggesting direct involvement of the fimbrial adhesin in this process. IRF-7 was further identified as a potent upstream regulator (-log (p-value) = 61), consistent with the effects in inoculated patients. In contrast, E. coli 83972fim transiently attenuated overall gene expression in human hosts, enhancing the effects of E. coli 83972. The inhibition of RNA processing and ribosomal assembly indicated a homeostatic rather than a pathogenic end-point. In parallel, the expression of specific ion channels and neuropeptide gene networks was transiently enhanced, in a FimH-dependent manner. The studies were performed to establish protective asymptomatic bacteriuria in human hosts and the reconstituted E. coli 83972 variants were developed to improve bacterial fitness for the human urinary tract. Unexpectedly, P fimbriae were able to drive a disease response, suggesting that like oncogene addiction in cancer, pathogens may be addicted to single super-virulence factors.
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| 19. |
- Ambite, Ines, et al.
(author)
-
Molecular Basis of Acute Cystitis Reveals Susceptibility Genes and Immunotherapeutic Targets
- 2016
-
In: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 12:10
-
Journal article (peer-reviewed)abstract
- Tissue damage is usually regarded as a necessary price to pay for successful elimination of pathogens by the innate immune defense. Yet, it is possible to distinguish protective from destructive effects of innate immune activation and selectively attenuate molecular nodes that create pathology. Here, we identify acute cystitis as an Interleukin-1 beta (IL-1β)-driven, hyper-inflammatory condition of the infected urinary bladder and IL-1 receptor blockade as a novel therapeutic strategy. Disease severity was controlled by the mechanism of IL-1β processing and mice with intact inflammasome function developed a moderate, self-limiting form of cystitis. The most severe form of acute cystitis was detected in mice lacking the inflammasome constituents ASC or NLRP-3. IL-1β processing was hyperactive in these mice, due to a new, non-canonical mechanism involving the matrix metalloproteinase 7- (MMP-7). ASC and NLRP-3 served as transcriptional repressors of MMP7 and as a result, Mmp7 was markedly overexpressed in the bladder epithelium of Asc-/- and Nlrp3-/- mice. The resulting IL-1β hyper-activation loop included a large number of IL-1β-dependent pro-inflammatory genes and the IL-1 receptor antagonist Anakinra inhibited their expression and rescued susceptible Asc-/- mice from bladder pathology. An MMP inhibitor had a similar therapeutic effect. Finally, elevated levels of IL-1β and MMP-7 were detected in patients with acute cystitis, suggesting a potential role as biomarkers and immunotherapeutic targets. The results reproduce important aspects of human acute cystitis in the murine model and provide a comprehensive molecular framework for the pathogenesis and immunotherapy of acute cystitis, one of the most common infections in man. Trial Registration: The clinical studies were approved by the Human Ethics Committee at Lund University (approval numbers LU106-02, LU236-99 and Clinical Trial Registration RTP-A2003, International Committee of Medical Journal Editors, www.clinicaltrials.gov).
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| 20. |
- Ambite, Ines, et al.
(author)
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Therapeutic Effects of IL-1RA against Acute Bacterial Infections, including Antibiotic-Resistant Strains
- 2024
-
In: Pathogens. - 2076-0817. ; 13:1
-
Journal article (peer-reviewed)abstract
- Innate immunity is essential for the anti-microbial defense, but excessive immune activation may cause severe disease. In this study, immunotherapy was shown to prevent excessive innate immune activation and restore the anti-bacterial defense. E. coli-infected Asc−/− mice develop severe acute cystitis, defined by IL-1 hyper-activation, high bacterial counts, and extensive tissue pathology. Here, the interleukin-1 receptor antagonist (IL-1RA), which inhibits IL-1 hyper-activation in acute cystitis, was identified as a more potent inhibitor of inflammation and NK1R- and substance P-dependent pain than cefotaxime. Furthermore, IL-1RA treatment inhibited the excessive innate immune activation in the kidneys of infected Irf3−/− mice and restored tissue integrity. Unexpectedly, IL-1RA also accelerated bacterial clearance from infected bladders and kidneys, including antibiotic-resistant E. coli, where cefotaxime treatment was inefficient. The results suggest that by targeting the IL-1 response, control of the innate immune response to infection may be regained, with highly favorable treatment outcomes, including infections caused by antibiotic-resistant strains.
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| 21. |
- Bodlund, Owe, et al.
(author)
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Validation of the self-report questionnaire DIP-Q in diagnosing DSM-IV personality disorders : a comparison of three psychiatric samples.
- 1998
-
In: Acta Psychiatrica Scandinavica. - : Wiley. - 0001-690X .- 1600-0447. ; 97:6, s. 433-9
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Journal article (peer-reviewed)abstract
- The DSM-IV section of the DSM-IV and ICD-10 Personality Questionnaire (DIP-Q) was used to screen for personality disorders in 448 subjects from three clinical samples (general and forensic psychiatric patients and candidates for psychotherapy) and a sample of 139 healthy volunteers. Differences between the samples with regard to patterns of personality pathology in relation to concurrent Axis I disorders and sociodemographic variables were analysed. The prevalence of personality disorders according to DIP-Q was 14% among the healthy volunteers, compared to 59% in the general psychiatric sample, 68% in the forensic psychiatric sample and up to 90% among psychotherapy candidates. Moreover, from a dimensional perspective (i.e. the number of fulfilled Axis II criteria), all clinical groups differed significantly from the control group in all specified personality dimensions and clusters. Dimensional DIP-Q cluster scores also discriminated significantly between the three clinical samples. Unexpectedly, the odds ratio for an Axis II disorder was nearly five times higher among psychotherapy applicants than among general psychiatric patients, independent of concomitant Axis I disorders, gender or age. The strongest association between DIP-Q score and Axis I disorders was found for depressive disorders, which more than doubled the odds ratio for a personality disorder diagnosis. This association could result from high true comorbidity, but could also be due to the fact that a concomitant depressive state can increase self-reported personality difficulties. The high prevalence among psychotherapy candidates may to some extent reflect help-seeking exaggeration of problems. These are aspects to consider when using the DIP-Q, which overall appears to discriminate well between different samples.
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| 22. |
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| 23. |
- Butler, Daniel S.C., et al.
(author)
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A bacterial protease depletes c-MYC and increases survival in mouse models of bladder and colon cancer
- 2021
-
In: Nature Biotechnology. - : Springer Science and Business Media LLC. - 1087-0156 .- 1546-1696. ; 39:6, s. 754-764
-
Journal article (peer-reviewed)abstract
- Is the oncogene MYC upregulated or hyperactive? In the majority of human cancers, finding agents that target c-MYC has proved difficult. Here we report specific bacterial effector molecules that inhibit cellular MYC (c-MYC) in human cells. We show that uropathogenic Escherichia coli (UPEC) degrade the c-MYC protein and attenuate MYC expression in both human cells and animal tissues. c-MYC protein was rapidly degraded by both cell-free bacterial lysates and the purified bacterial protease Lon. In mice, intravesical or peroral delivery of Lon protease delayed tumor progression and increased survival in MYC-dependent bladder and colon cancer models, respectively. These results suggest that bacteria have evolved strategies to control c-MYC tissue levels in the host and that the Lon protease shows promise for therapeutic targeting of c-MYC in cancer.
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| 24. |
- Butler, Daniel S.C., et al.
(author)
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Neuroepithelial control of mucosal inflammation in acute cystitis
- 2018
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8, s. 1-15
-
Journal article (peer-reviewed)abstract
- The nervous system is engaged by infection, indirectly through inflammatory cascades or directly, by bacterial attack on nerve cells. Here we identify a neuro-epithelial activation loop that participates in the control of mucosal inflammation and pain in acute cystitis. We show that infection activates Neurokinin-1 receptor (NK1R) and Substance P (SP) expression in nerve cells and bladder epithelial cells in vitro and in vivo in the urinary bladder mucosa. Specific innate immune response genes regulated this mucosal response, and single gene deletions resulted either in protection (Tlr4−/− and Il1b−/− mice) or in accentuated bladder pathology (Asc−/− and Nlrp3−/− mice), compared to controls. NK1R/SP expression was lower in Tlr4−/− and Il1b−/− mice than in C56BL/6WT controls but in Asc−/− and Nlrp3−/− mice, NK1R over-activation accompanied the exaggerated disease phenotype, due, in part to transcriptional de-repression of Tacr1. Pharmacologic NK1R inhibitors attenuated acute cystitis in susceptible mice, supporting a role in disease pathogenesis. Clinical relevance was suggested by elevated urine SP levels in patients with acute cystitis, compared to patients with asymptomatic bacteriuria identifying NK1R/SP as potential therapeutic targets. We propose that NK1R and SP influence the severity of acute cystitis through a neuro-epithelial activation loop that controls pain and mucosal inflammation.
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| 25. |
- Chaudhuri, Arunima, et al.
(author)
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Protein-dependent membrane interaction of a partially disordered protein complex with oleic acid : Implications for cancer lipidomics
- 2016
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
-
Journal article (peer-reviewed)abstract
- Bovine α-lactalbumin (BLA) forms cytotoxic complexes with oleic acid (OA) that perturbs tumor cell membranes, but molecular determinants of these membrane-interactions remain poorly understood. Here, we aim to obtain molecular insights into the interaction of BLA/BLA-OA complex with model membranes. We characterized the folding state of BLA-OA complex using tryptophan fluorescence and resolved residue-specific interactions of BLA with OA using molecular dynamics simulation. We integrated membrane-binding data using a voltage-sensitive probe and molecular dynamics (MD) to demonstrate the preferential interaction of the BLA-OA complex with negatively charged membranes. We identified amino acid residues of BLA and BLA-OA complex as determinants of these membrane interactions using MD, functionally corroborated by uptake of the corresponding α-LA peptides across tumor cell membranes. The results suggest that the α-LA component of these cytotoxic complexes confers specificity for tumor cell membranes through protein interactions that are maintained even in the lipid complex, in the presence of OA.
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| 26. |
- Connell, H., et al.
(author)
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Bacterial attachment to uro-epithelial cells : mechanisms and consequences.
- 1997
-
In: Advances in dental research. - : SAGE Publications. - 0895-9374 .- 1544-0737. ; 11:1, s. 50-58
-
Research review (peer-reviewed)abstract
- Microbial attachment to mucosal surfaces is a first step in mucosal infection. Specific interactions between microbial surface ligands and host receptors influence the distribution of microbes in their sites of infection. Adhesion has often been regarded as a sufficient end point, explaining tissue tropism and bacterial persistence at mucosal sites. Adherence, however, is also a virulence factor through which microbes gain access to host tissues, upset the integrity of the mucosal barrier, and cause disease. The induction of mucosal inflammation is one aspect of this process. Bacterial attachment to mucosal surfaces activates the production of pro-inflammatory cytokines that cause both local and systemic inflammation. Epithelial cells are one source of these cytokines. The binding of fimbrial lectins to epithelial cell receptors triggers transmembrane signaling events that upregulate cytokine-specific mRNA and increase cytokine secretion. P fimbriae that bind the globoseries of glycolipids cause the release of ceramides and activation of the ceramide signaling pathway which contributes to the IL-6 response. Spread of cytokines and other pro-inflammatory mediators from the local site contributes to the symptoms and signs of infection.
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| 27. |
- Connell, H., et al.
(author)
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Type 1 fimbrial expression enhances Escherichia coli virulence for the urinary tract
- 1996
-
In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424. ; 93:18, s. 9827-9832
-
Journal article (peer-reviewed)abstract
- Type 1 fimbriae are adhesion organelles expressed by many Gram-negative bacteria. They facilitate adherence to mucosal surfaces and inflammatory cells in vitro, but their contribution to virulence has not been defined. This study presents evidence that type 1 fimbriae increase the virulence of Escherichia coli for the urinary tract by promoting bacterial persistence and enhancing the inflammatory response to infection. In a clinical study, we observed that disease severity was greater in children infected with E. coli O1:K1:H7 isolates expressing type 1 fimbriae than in those infected with type 1 negative isolates of the same serotype. The E. coli O1:K1:H7 isolates had the same electrophoretic type, were hemolysin-negative, expressed P fimbriae, and carried the fim DNA sequences. When tested in a mouse urinary tract infection model, the type 1-positive E. coli O1:K1:H7 isolates survived in higher numbers, and induced a greater neutrophil influx into the urine, than O1:K1:H7 type 1-negative isolates. To confirm a role of type 1 fimbriae, a fimH null mutant (CNI016) was constructed from an O1:K1:H7 type 1-positive parent. E. coli CNI016 had reduced survival and inflammatogenicity in the mouse urinary tract infection model. E. coli CNI016 reconstituted with type 1 fimbriae (E. coli CN1018) had restored virulence similar to that of the wild- type parent strain. These results show that type 1 fimbriae in the genetic background of a uropathogenic strain contribute to the pathogenesis of E. coli in the urinary tract.
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| 28. |
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| 29. |
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| 30. |
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| 31. |
- Hang, L, et al.
(author)
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Cytokine repertoire of epithelial cells lining the human urinary tract
- 1998
-
In: The Journal of urology. - 0022-5347. ; 159:6, s. 92-2185
-
Journal article (peer-reviewed)abstract
- PURPOSE: To examine the cytokine profile of epithelial cells lining the human urinary tract with the aim of differentiating between the constitutive and disease-related cytokine production in these tissues.MATERIALS AND METHODS: Sections from the renal pelvis, ureter, bladder or urethra were obtained from 22 patients undergoing urinary tract surgery and were stained with monoclonal antibodies to interleukin(IL)-1beta, IL-4, IL-6, IL-8, interferon gamma (IFNgamma) and transforming growth factor beta (TGFbeta). Sections were classified according to the presence or absence of disease in the tissue.RESULTS: Epithelial cells lining the renal pelvis, ureter, bladder or urethra all stained for IL-8 and TGFbeta (100%) in disease-free tissues and sections with cancer or interstitial cystitis (IC). In contrast, staining for IL-1beta, IL-4, IL-6 and IFNgamma varied with the disease state of the patient. Epithelial IL-1beta staining was absent (0%) in sections from healthy bladder, but positive in tissues with IC or cancer-associated pathology (50 to 100%). IL-6 staining was detected in the epithelial layer of several patients with IC or cancer related pathology, but only in cells with non-epithelial morphology and not in disease-free tissues. IFNgamma and IL-4 staining were only observed in patients with IC and only in cells with non-epithelial morphology.CONCLUSIONS: The results show that epithelial cells from all parts of the urinary tract constitutively produce IL-8 and TGFbeta and suggest that the production of other cytokines varies with the disease of the patient. Constitutive cytokine production provides the basis for a rapid host response, in the defense against mucosal attack by microbes or toxic agents.
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| 32. |
- Hansen, Jesper S., et al.
(author)
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Peptide-Oleate Complexes Create Novel Membrane-Bound Compartments
- 2020
-
In: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 37:11, s. 3083-3093
-
Journal article (peer-reviewed)abstract
- A challenging question in evolutionary theory is the origin of cell division and plausible molecular mechanisms involved. Here, we made the surprising observation that complexes formed by short alpha-helical peptides and oleic acid can create multiple membrane-enclosed spaces from a single lipid vesicle. The findings suggest that such complexes may contain the molecular information necessary to initiate and sustain this process. Based on these observations, we propose a new molecular model to understand protocell division.
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| 33. |
- HEDGES, S., et al.
(author)
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Cyclosporin A does not Inhibit IL‐lα‐Induced Epithelial Cell IL‐6 Secretion
- 1993
-
In: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 37:5, s. 581-586
-
Journal article (peer-reviewed)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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| 34. |
- Hedges, S., et al.
(author)
-
Cytokines induce an epithelial cell cytokine response
- 1995
-
In: Advances in Experimental Medicine and Biology. - Boston, MA : Springer US. - 0065-2598. ; 371:A, s. 189-193
-
Journal article (peer-reviewed)abstract
- Intravesical inoculation of gram negative bacteria or isolated bacterial products into mice induces an IL-6 response which can be measured within miutes of the infection.1,2 In such infections, IL-6 is initially detected in the urine and subsequently in the serum. Similar IL-6 responses were found in human patients deliberately colonized in the urinary tract with E. coli Hu7343. IL-6 was secreted intermittantly into the urine in response to continuous bacterial infection in humans, but was not detected in serum. The rapid secretion of IL-6 into urine after bacterial stimulation, and the separation of local from systemic secretion in both humans and mice suggested that IL-6 was produced at the site of infection. Since epithelial cells dominate the naive urinary tract mucosal surface, we suggested that epithelial cells are one source of mucosally produced cytokines.4 Epithelial cell lines of urinary tract origin secrete IL-6 and IL-8, and can produce other cytokines after bacterial stimulation.5–7 In this paper we demonstrate that epithelial cell lines of urinary tract origin can respond to exogenous cytokines. This response includes the up-regulation of a variety of cytokine mRNA species as well as secretion of IL-6 and IL-8. Furthermore, this response is specific to the stimulus used, with different cytokine mRNA species induced by different cytokine stimuli.
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| 35. |
- Ho, James C.S., et al.
(author)
-
A scientific journey from discovery to validation of efficacy in cancer patients : HAMLET and alpha1-oleate
- 2021
-
In: Molecular and Cellular Oncology. - : Informa UK Limited. - 2372-3556. ; 8:5
-
Journal article (peer-reviewed)abstract
- The protein-lipid complex alpha1-oleate, derived from HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells), is identified as a molecular entity with significant therapeutic potential. Structural characterization of the complex and results of a successful placebo-controlled clinical trial are presented.
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| 36. |
- Ho, James C S, et al.
(author)
-
HAMLET – A protein-lipid complex with broad tumoricidal activity
- 2017
-
In: Biochemical and Biophysical Research Communications. - : Elsevier BV. - 0006-291X. ; 482:3, s. 454-458
-
Research review (peer-reviewed)abstract
- HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) is a tumoricidal protein-lipid complex with broad effects against cancer cells of different origin. The therapeutic potential is emphasized by a high degree of specificity for tumor tissue. Here we review early studies of HAMLET, in collaboration with the Orrenius laboratory, and some key features of the subsequent development of the HAMLET project. The early studies focused on the apoptotic response that accompanies death in HAMLET treated tumor cells and the role of mitochondria in this process. In subsequent studies, we have identified a sequence of interactions that starts with the membrane integration of HAMLET and the activation of ion fluxes followed by HAMLET internalization, progressive inhibition of MAPK kinases and GTPases and sorting of HAMLET to different cellular compartments, including the nuclei. Therapeutic efficacy of HAMLET has been demonstrated in animal models of glioblastoma, bladder cancer and intestinal cancer. In clinical studies, HAMLET has been shown to target skin papillomas and bladder cancers. The findings identify HAMLET as a new drug candidate with promising selectivity for cancer cells and a strong therapeutic potential.
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| 37. |
- Ho, James C.S., et al.
(author)
-
Lipid bilayer composition as a determinant of cancer cell sensitivity to tumoricidal protein-lipid complexes
- 2022
-
In: BioFactors. - : Wiley. - 0951-6433 .- 1872-8081. ; 48:5, s. 1145-1159
-
Journal article (peer-reviewed)abstract
- Complexes formed by the alpha1 N-terminal peptide of alpha-lactalbumin and oleic acid (alpha1-oleate) interact with lipid bilayers. Plasma membrane perturbations trigger tumor cell death but normal differentiated cells are more resistant, and their plasma membranes are less strongly affected. This study examined membrane lipid composition as a determinant of tumor cell reactivity. Bladder cancer tissue showed a higher abundance of unsaturated lipids enriched in phosphatidylcholine, PC (36:4) and PC (38:4), and sphingomyelin, SM (36:1) than healthy bladder tissue, where saturated lipids predominated and the lipid extracts from bladder cancer tissue inhibited the tumoricidal effect of the complex more effectively than healthy tissue extracts. Furthermore, unsaturated PC in solution inhibited tumor cell death, and the complex interacted with giant unilamellar vesicles formed by PC, confirming the affinity of alpha1-oleate for fluid membranes enriched in PC. Quartz Crystal Microbalance with dissipation monitoring (QCM-D) detected a preference of the complex for the liquid-disordered phase, suggesting that the insertion into PC-based membranes and the resulting membrane perturbations are influenced by membrane lipid saturation. The results suggest that the membrane lipid composition is functionally important and that specific unsaturated membrane lipids may serve as “recognition motifs” for broad-spectrum tumoricidal molecules such as alpha1-oleate.
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| 38. |
- Håkansson, Anders P, et al.
(author)
-
A folding variant of alpha-lactalbumin with bactericidal activity against Streptococcus pneumoniae
- 2000
-
In: Molecular Microbiology. - : Wiley. - 0950-382X .- 1365-2958. ; 35:3, s. 589-600
-
Journal article (peer-reviewed)abstract
- This study describes an alpha-lactalbumin folding variant from human milk with bactericidal activity against antibiotic-resistant and -susceptible strains of Streptococcus pneumoniae. The active complex precipitated with the casein fraction at pH 4.6 and was purified from casein by a combination of anion exchange and gel chromatography. Unlike other casein components, the active complex was retained on the ion-exchange matrix and eluted only with high salt. The eluted fraction showed N-terminal and mass spectrometric identity with human milk alpha-lactalbumin, but native alpha-lactalbumin had no bactericidal effect. Spectroscopic analysis demonstrated that the active form of the molecule was in a different folding state, with secondary structure identical to alpha-lactalbumin from human milk whey, but fluctuating tertiary structure. Native alpha-lactalbumin could be converted to the active bactericidal form by ion-exchange chromatography in the presence of a cofactor from human milk casein, characterized as a C18:1 fatty acid. Analysis of the antibacterial spectrum showed selectivity for streptococci; Gram-negative and other Gram-positive bacteria were resistant. The folding variant of alpha-lactalbumin is a new example of naturally occurring molecules with antimicrobial activity.
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| 39. |
- Håkansson, Anders P, et al.
(author)
-
Apoptosis induced by a human milk protein
- 1995
-
In: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 92:17, s. 8064-8068
-
Journal article (peer-reviewed)abstract
- To the breast-fed infant, human milk is more than a source of nutrients; it furnishes a wide array of molecules that restrict microbes, such as antibodies, bactericidins, and inhibitors of bacterial adherence. However, it has rarely been considered that human milk may also contain substances bioactive toward host cells. While investigating the effect of human milk on bacterial adherence to a human lung cancer cell line, we were surprised to discover that the milk killed the cells. Analysis of this effect revealed that a component of milk in a particular physical state--multimeric alpha-lact-albumin--is a potent Ca(2+)-elevating and apoptosis-inducing agent with broad, yet selective, cytotoxic activity. Multimeric alpha-lactalbumin killed all transformed, embryonic, and lymphoid cells tested but spared mature epithelial elements. These findings raise the possibility that milk contributes to mucosal immunity not only by furnishing antimicrobial molecules but also by policing the function of lymphocytes and epithelium. Finally, analysis of the mechanism by which multimeric alpha-lactalbumin induces apoptosis in transformed epithelial cells could lead to the design of antitumor agents.
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| 40. |
- Johanson, I M, et al.
(author)
-
Pap, papG and prsG DNA sequences in Escherichia coli from the fecal flora and the urinary tract.
- 1993
-
In: Microbial pathogenesis. - : Elsevier BV. - 0882-4010. ; 15:2, s. 121-9
-
Journal article (peer-reviewed)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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| 41. |
- Karpman, D, et al.
(author)
-
Cytokines in childhood hemolytic uremic syndrome and thrombotic thrombocytopenic purpura
- 1995
-
In: Pediatric Nephrology. - 0931-041X. ; 9:6, s. 9-694
-
Journal article (peer-reviewed)abstract
- Serum and urine cytokines were analyzed in children with hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Interleukin-6 (IL-6) was elevated in the serum of 33 of 35 children with HUS (94%) and in 2 of 2 children with recurrent TTP. Serum IL-6 was higher in children with HUS who developed anuria, extrarenal manifestations during the acute phase of illness and/or chronic renal sequelae. Tumor necrosis factor-alpha (TNF-alpha) was detected in the serum of 7 patients with HUS (20%) and 1 patient with TTP. IL-6 and TNF-alpha were elevated in the urine of 4 of 4 children with HUS and 2 of 2 children with TTP. Urinary levels were higher than serum levels, suggesting local production of cytokines in the urinary tract. Sequential serum and urine samples showed that IL-6 levels varied with disease activity. IL-6 and TNF-alpha were not detected in the serum (n = 25) and urine (n = 15) of healthy children. We conclude that IL-6 in urine may be used to monitor disease activity in HUS and TTP.
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| 42. |
- Karpman, D, et al.
(author)
-
The role of lipopolysaccharide and Shiga-like toxin in a mouse model of Escherichia coli O157:H7 infection
- 1997
-
In: Journal of Infectious Diseases. - : Oxford University Press (OUP). - 0022-1899 .- 1537-6613. ; 175:3, s. 20-611
-
Journal article (peer-reviewed)abstract
- The role of lipopolysaccharide (LPS) and Shiga-like toxin (SLT) in the pathogenesis of hemolytic uremic syndrome (HUS) was studied in a mouse model. Mice inoculated intragastrically with Escherichia coli O157:H7 developed gastrointestinal, neurologic, and systemic symptoms, necrotic foci in the colon, glomerular and tubular histopathology, and fragmented erythrocytes. LPS-responder (C3H/HeN) mice developed a combination of neurologic and systemic symptoms, whereas LPS-nonresponder (C3H/HeJ) mice had a biphasic course of disease, first developing systemic symptoms and later severe neurologic symptoms. Mice inoculated with SLT-II-positive strains developed severe neurotoxic symptoms and a higher frequency of systemic symptoms and glomerular pathology compared with SLT-II-negative strains. Anti-SLT-II antibodies protected against these symptoms and pathology. These results demonstrate that this model could be used to study aspects of human HUS and that both LPS and SLT are important for disease development.
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| 43. |
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| 44. |
- Lodinová-Zádníková, R, et al.
(author)
-
The antibody response in breast-fed and non-breast-fed infants after artificial colonization of the intestine with Escherichia coli O83.
- 1991
-
In: Pediatric research. - : Springer Science and Business Media LLC. - 0031-3998 .- 1530-0447. ; 29:4 Pt 1, s. 396-9
-
Journal article (peer-reviewed)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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| 45. |
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| 46. |
- Mabbett, Amanda N., et al.
(author)
-
Virulence properties of asymptomatic bacteriuria Escherichia coli
- 2009
-
In: International Journal of Medical Microbiology. - : Elsevier BV. - 1618-0607 .- 1438-4221. ; 299:1, s. 53-63
-
Journal article (peer-reviewed)abstract
- In asymptomatic bacteriuria (ABU), bacteria colonize the urinary tract without provoking symptoms. Here, we compared the virulence properties of a collection of ABU Escherichia coli strains to cystitis and pyelonephritis strains. Specific urinary tract infection (UTI)-associated virulence genes, hemagglutination characteristics, siderophore production, hemolysis, biofilm formation, and the ability of strains to adhere to and induce cytokine responses in epithelial cells were analyzed. ABU strains were phylogenetically related to strains that cause symptomatic UTI. However, the virulence properties of the ABU strains were variable and dependent on a combination of genotypic and phenotypic factors. Most ABU strains adhered poorly to epithelial cells; however, we also identified a subgroup of strongly adherent strains that were unable to stimulate an epithelial cell IL-6 cytokine response. Poor immune activation may represent one mechanism whereby ABU E coli evade immune detection after the establishment of bacteriuria. (C) 2008 Elsevier GmbH. All rights reserved.
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| 47. |
- Nadeem, Aftab, et al.
(author)
-
Beta-sheet-specific interactions with heat shock proteins define a mechanism of delayed tumor cell death in response to HAMLET
- 2019
-
In: Journal of Molecular Biology. - : Elsevier BV. - 0022-2836. ; 431:14, s. 2612-2627
-
Journal article (peer-reviewed)abstract
- As chaperones, heat shock proteins (HSPs)protect host cells against misfolded proteins that constitute a by-product of protein synthesis. Certain HSPs are also expressed on the surface of tumor cells, possibly to scavenge extracellular unfolded protein ligands and prevent them from becoming cytotoxic. HAMLET—a complex of partially unfolded alpha-lactalbumin and oleic acid—is relying on its N-terminal alpha-helical domain to perturb tumor cell membranes, and the cells die as a consequence of this interaction. Here we show that in parallel, cell surface HSPs bind the beta-sheet domain of alpha-lactalbumin and activate a temporarily protective loop, involving vesicular uptake and lysosomal accumulation. Later, HAMLET destroys lysosomal membrane integrity, and HAMLET release kills the remaining tumor cells. HSPs were identified as HAMLET targets in a proteomic screen and Hsp70-specific antibodies or shRNAs inhibited HAMLET uptake by tumor cells, which showed increased Hsp70 surface expression compared to differentiated cells. The results suggest that HAMLET engages tumor cells by two parallel recognition mechanisms, defined by alpha-helical- or beta-sheet domains of alpha-lactalbumin and resulting in an immediate death response, or a delay due to transient accumulation of the complex in the lysosomes. This dual response pattern was conserved among tumor cells but not seen in normal, differentiated cells. By two different mechanisms, HAMLET thus achieves a remarkably efficient elimination of tumor cells.
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| 48. |
- Nadeem, Aftab, et al.
(author)
-
Protein receptor-independent plasma membrane remodeling by HAMLET: a tumoricidal protein-lipid complex.
- 2015
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
-
Journal article (peer-reviewed)abstract
- A central tenet of signal transduction in eukaryotic cells is that extra-cellular ligands activate specific cell surface receptors, which orchestrate downstream responses. This ''protein-centric" view is increasingly challenged by evidence for the involvement of specialized membrane domains in signal transduction. Here, we propose that membrane perturbation may serve as an alternative mechanism to activate a conserved cell-death program in cancer cells. This view emerges from the extraordinary manner in which HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) kills a wide range of tumor cells in vitro and demonstrates therapeutic efficacy and selectivity in cancer models and clinical studies. We identify a ''receptor independent" transformation of vesicular motifs in model membranes, which is paralleled by gross remodeling of tumor cell membranes. Furthermore, we find that HAMLET accumulates within these de novo membrane conformations and define membrane blebs as cellular compartments for direct interactions of HAMLET with essential target proteins such as the Ras family of GTPases. Finally, we demonstrate lower sensitivity of healthy cell membranes to HAMLET challenge. These features suggest that HAMLET-induced curvature-dependent membrane conformations serve as surrogate receptors for initiating signal transduction cascades, ultimately leading to cell death.
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| 49. |
- Otto, Gisela, et al.
(author)
-
Virulence factors and pap genotype in Escherichia coli isolates from women with acute pyelonephritis, with or without bacteremia.
- 1993
-
In: Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. - 1058-4838. ; 17:3, s. 448-56
-
Journal article (peer-reviewed)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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| 50. |
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