| 1. |
- Bogefors, Jesper, et al.
(author)
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LEAP-2, LL-37 and RNase7 in tonsillar tissue: downregulated expression in seasonal allergic rhinitis.
- 2014
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In: Pathogens and Disease. - 2049-632X. ; 72:1, s. 55-60
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Journal article (peer-reviewed)abstract
- In the upper airway, the production of antimicrobial peptides (AMPs) protects against bacteria, viruses and fungi. Previous investigations have revealed downregulated expression of AMPs in different manifestations of allergic disease. In this study, we examined the expression of LL-37, RNase7 and LEAP-2 in tonsillar tissue and studied a possible relation to seasonal allergic rhinitis (SAR).
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| 2. |
- Olivares, Nesty, et al.
(author)
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The protective effect of immunoglobulin in murine tuberculosis is dependent on IgG glycosylation
- 2013
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In: Pathogens and Disease. - 2049-632X. ; 69:3, s. 176-183
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Journal article (peer-reviewed)abstract
- Antibodies have demonstrated having a protective effect in animal models of tuberculosis (TB). These experiments have considered the specificity of antigen recognition and the different isotypes and subclasses as significant contributors of this effect. However, the carbohydrate chain heterogeneity on the Fc region of IgG (Fc-IgG) can play an important role in modulating the immune response. Patients with TB usually have high titers of specific IgG; however, the carbohydrate associated with Fc-IgG usually lacks galactose. To assess the effect of this abnormal IgG in murine pulmonary TB, we evaluated the specificity of recognition to Mycobacterium tuberculosis antigens in vitro and protective effects in vivo comparing human intravenous immunoglobulin (IVIg) and IVIg treated with an endoglycosidase to remove the glycan residues (EndoS-treated IVIg). Our results showed similar antigen recognition. The study of distribution and kinetics of IVIg in serum and bronchial lavage after intraperitoneal (i.p.) administration in mice showed that IVIg circulates for 21days. Finally, the protective effect of intact and EndoS-treated IVIg administered by i.p was studied in a murine model of progressive TB. IVIg treatment caused reduction in pulmonary bacilli loads, larger granulomas, and less pneumonia, while animals treated with EndoS-treated IVIg were not protected compared with control animals. Thus, IVIg has a protective activity in experimental pulmonary TB, and this effect requires intact Fc oligosaccharides. This work compares conventional fully glycosylated and deglycosylated IVIg determining their mycobacterial antigen recognition by two dimensional Western-blotting, specific mycobacterial antigen recognition by ELISA, kinetics of distribution after intraperitoneal administration, and protective efficiency by evaluating pulmonary bacilli loads and tissue damage after i.p. administration during early infection in a model of progressive pulmonary tuberculosis. The results add to the growing body of information that antibodies have a protective effect at least in animal models of tuberculosis.
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| 3. |
- Pihl, Maria, et al.
(author)
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Biofilm formation by Staphylococcus epidermidis on peritoneal dialysis catheters and the effects of extracellular products from Pseudomonas aeruginosa.
- 2013
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In: Pathogens and Disease. - : Blackwell Publishing Ltd. - 2049-632X. ; 67:3, s. 192-198
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Journal article (peer-reviewed)abstract
- Biofilm formation by Staphylococcus epidermidis is a cause of infections related to peritoneal dialysis (PD). We have used a PD catheter flow-cell model in combination with confocal scanning laser microscopy and atomic force microscopy to study biofilm formation by S. epidermidis. Adherence to serum-coated catheters was four times greater than to uncoated ones, suggesting that S. epidermidis binds to serum proteins on the catheter surface. Pseudomonas aeruginosa biofilm supernatant interfered with the formation of a serum protein coat thereby reducing the capacity for biofilm formation in S. epidermidis. Supernatants from ΔpelA, ΔpslBCD and ΔrhlAB strains of P. aeruginosa showed no differences from the wild-type supernatant indicating that the effect on serum coat formation was not due to rhamnolipids or the PelA and PslBCD polysaccharides. Supernatant from P. aeruginosa also dispersed established S. epidermidis biofilms. Supernatants lacking PelA or PslBCD showed no differences from the wild type but that from a ΔrhlAB strain, showed reduced, but not abolished, capacity for dispersal. This suggests that rhamnolipids are involved but not wholly responsible for the effect. Thus, supernatants from P. aeruginosa contain promising substances for the prevention and treatment of biofilm infections, although further work is required to identity more active components.
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| 4. |
- Sigar, Ira M., et al.
(author)
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Plasmid deficiency in urogenital isolates of Chlamydia trachomatis reduces infectivity and virulence in a mouse model
- 2014
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In: Pathogens and Disease. - : Wiley-Blackwell. - 2049-632X. ; 70:1, s. 61-69
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Journal article (peer-reviewed)abstract
- We hypothesized that the plasmid of urogenital isolates of Chlamydia trachomatis would modulate infectivity and virulence in a mouse model. To test this hypothesis, we infected female mice in the respiratory or urogenital tract with graded doses of a human urogenital isolate of C.trachomatis, serovar F, possessing the cognate plasmid. For comparison, we inoculated mice with a plasmid-free serovar F isolate. Following urogenital inoculation, the plasmid-free isolate displayed significantly reduced infectivity compared with the wild-type strain with the latter yielding a 17-fold lower infectious dose to yield 50% infection. When inoculated via the respiratory tract, the plasmid-free isolate exhibited reduced infectivity and virulence (as measured by weight change) when compared to the wild-type isolate. Further, differences in infectivity, but not in virulence were observed in a C.trachomatis, serovar E isolate with a deletion within the plasmid coding sequence 1 when compared to a serovar E isolate with no mutations in the plasmid. We conclude that plasmid loss reduces virulence and infectivity in this mouse model. These findings further support a role for the chlamydial plasmid in infectivity and virulence in vivo.
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| 5. |
- Wang, Yibing, et al.
(author)
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Transformation of a plasmid-free, genital tract isolate of Chlamydia trachomatis with a plasmid vector carrying a deletion in CDS6 revealed that this gene regulates inclusion phenotype
- 2013
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In: Pathogens and Disease. - 2049-632X. ; 67:2, s. 100-103
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Journal article (peer-reviewed)abstract
- The development of a plasmid-based genetic transformation protocol for Chlamydia trachomatis provides the basis for the detailed investigation of the function of the chlamydial plasmid and its individual genes or coding sequences (CDS). In this study we constructed a plasmid vector with CDS6 deleted (pCDS6KO) from the original Escherichia coli/C. trachomatis shuttle vector pGFP::SW2. pCDS6KO was transformed into a clinical isolate of C. trachomatis from Sweden that is plasmid-free (C. trachomatis SWFP-). Penicillin-resistant transformants expressing the green fluorescent protein were selected. These transformants did not stain with iodine, indicating that this property is regulated by CDS6 or its gene product. In addition, mature inclusions of C. trachomatis SWFP-transformed by pCDS6KO displayed an identical morphological phenotype to the untransformed plasmid-free recipient host. In this phenotype the morphology of inclusions was altered with the chlamydiae lining the periphery of the inclusion leaving a 'hole' in the centre. These green fluorescent inclusions appear 'doughnut-shaped' with an empty centre when examined under blue light, giving rise to a characteristic 'black hole' phenotype. Our study demonstrates the power of the new genetic system for investigating chlamydial gene function using gene deletion technology.
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| 6. |
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| 7. |
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| 8. |
- Ericson, Dan, et al.
(author)
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Salivary IgA response to probiotic bacteria and mutans streptococci after the use of chewing gum containing Lactobacillus reuteri
- 2013
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In: Pathogens and Disease. - : Wiley-Blackwell. - 2049-632X. ; 68:3, s. 82-87
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Journal article (peer-reviewed)abstract
- We investigated whether ingestion of probiotic bacteria could influence salivary IgA levels, specific anti-mutans streptococci IgA levels and specific antibodies towards the ingested probiotic bacterium. The study was a randomised, double-blind, placebo-controlled trial, where the test group (n = 11) received twice daily chewing of gum containing Lactobacillus reuteri (2 9 108 CFU per dose) and the control group (n = 12) received placebo. Resting saliva was collected before and after 12 weeks of treatment and 4 weeks after end of treatment. Total salivary IgA concentrations were measured by ELISA. Specific IgA reactivity was determined using a whole-cell ELISA. Results were expressed as % IgA per protein in saliva. The level of total IgA% per protein increased significantly between pretreatment levels (13.5%) and follow-up treatment levels (14.4%) within the test group only (P < 0.05). No changes were seen in the control group during the trial. The level of probiotic-reactive antibodies decreased significantly between pre- and post-treatment samples (from 12.2% to 9.0%, P < 0.05) in the test group. Similarly, the level of specific mutans streptococci antibodies decreased significantly between pre- and post-treatment samples (P < 0.05) in the test group only (for Streptococcus mutans from 20.1% to 15.0%; for Streptococcus sobrinus from 7.4% to 5.3%). Ingestion of probiotic bacteria might influence the adaptive immune response of the host.
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| 9. |
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| 10. |
- Shankar, Esaki M., et al.
(author)
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HIV-Mycobacterium tuberculosis co-infection: a `danger-couplemodel of disease pathogenesis
- 2014
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In: PATHOGENS AND DISEASE. - : Wiley / Blackwell Publishing Ltd. - 2049-632X. ; 70:2, s. 110-118
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Research review (peer-reviewed)abstract
- Tuberculosis (TB) and human immunodeficiency virus (HIV) infection interfere and impact the pathogenesis phenomena of each other. Owing to atypical clinical presentations and diagnostic complications, HIV/TB co-infection continues to be a menace for healthcare providers. Although the increased access to highly active antiretroviral therapy (HAART) has led to a reduction in HIV-associated opportunistic infections and mortality, the concurrent management of HIV/TB co-infection remains a challenge owing to adverse effects, complex drug interactions, overlapping toxicities and tuberculosis -associated immune reconstitution inflammatory syndrome. Several hypotheses have been put forward for the exacerbation of tuberculosis by HIV and vice versa supported by immunological studies. Discussion on the mechanisms produced by infectious cofactors with impact on disease pathology could shed light on how to design potential interventions that could decelerate disease progression. With no vaccine for HIV and lack of an effective vaccine for tuberculosis, it is essential to design strategies against HIV–TB co-infection.
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