| 1. |
- Omer, Abubakr A. M., 1982-, et al.
(författare)
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Plantaricin NC8 αβ rapidly and efficiently inhibits flaviviruses and SARS-CoV-2 by disrupting their envelopes
- 2022
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 17:11
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Tidskriftsartikel (refereegranskat)abstract
- Potent broad-spectrum antiviral agents are urgently needed to combat existing and emerging viral infections. This is particularly important considering that vaccine development is a costly and time consuming process and that viruses constantly mutate and render the vaccine ineffective. Antimicrobial peptides (AMP), such as bacteriocins, are attractive candidates as antiviral agents against enveloped viruses. One of these bacteriocins is PLNC8 αβ, which consists of amphipathic peptides with positive net charges that display high affinity for negatively charged pathogen membrane structures, including phosphatidylserine rich lipid membranes of viral envelopes. Due to the morphological and physiological differences between viral envelopes and host cell plasma membranes, PLNC8 αβ is thought to have high safety profile by specifically targeting viral envelopes without effecting host cell membranes. In this study, we have tested the antiviral effects of PLNC8 αβ against the flaviviruses Langat and Kunjin, coronavirus SARS-CoV-2, influenza A virus (IAV), and human immunodeficiency virus-1 (HIV-1). The concentration of PLNC8 αβ that is required to eliminate all the infective virus particles is in the range of nanomolar (nM) to micromolar (μM), which is surprisingly efficient considering the high content of cholesterol (8–35%) in their lipid envelopes. We found that viruses replicating in the endoplasmic reticulum (ER)/Golgi complex, e.g. SARS-CoV-2 and flaviviruses, are considerably more susceptible to PLNC8 αβ, compared to viruses that acquire their lipid envelope from the plasma membrane, such as IAV and HIV-1. Development of novel broad-spectrum antiviral agents can significantly benefit human health by rapidly and efficiently eliminating infectious virions and thereby limit virus dissemination and spreading between individuals. PLNC8 αβ can potentially be developed into an effective and safe antiviral agent that targets the lipid compartments of viral envelopes of extracellular virions, more or less independent of virus antigenic mutations, which faces many antiviral drugs and vaccines.
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| 2. |
- Bengtsson, Torbjörn, 1955-, et al.
(författare)
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Secreted gingipains from Porphyromonas gingivalis colonies exert potent immunomodulatory effects on human gingival fibroblasts
- 2015
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Ingår i: Microbiological Research. - : Elsevier BV. - 0944-5013 .- 1618-0623. ; 178, s. 18-26
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Tidskriftsartikel (refereegranskat)abstract
- Periodontal pathogens, including Polphyromonas gingivalis, can form biofilms in dental pockets and cause inflammation, which is one of the underlying mechanisms involved in the development of periodontal disease, ultimately leading to tooth loss. Although P. gingivalis is protected in the biofilm, it can still cause damage and modulate inflammatory responses from the host, through secretion of microvesicles containing proteinases. The aim of this study was to evaluate the role of cysteine proteinases in P. gingivalis colony growth and development, and subsequent immunomodulatory effects on human gingival fibroblast. By comparing the wild type W50 with its gingipain deficient strains we show that cysteine proteinases are required by P. gingivalis to form morphologically normal colonies. The lysine-specific proteinase (Kgp), but not arginine-specific proteinases (Rgps), was associated with immunomodulation. P. gingivalis with Kgp affected the viability of gingival fibroblasts and modulated host inflammatory responses, including induction of TGF-beta 1 and suppression of CXCL8 and IL-6 accumulation. These results suggest that secreted products from P. gingivalis, including proteinases, are able to cause damage and significantly modulate the levels of inflammatory mediators, independent of a physical host-bacterial interaction. This study provides new insight of the pathogenesis of P. gingivalis and suggests gingipains as targets for diagnosis and treatment of periodontitis.
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| 3. |
- Bengtsson, Torbjörn, 1955-, et al.
(författare)
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Dual action of bacteriocin PLNC8 alpha beta through inhibition of Porphyromonas gingivalis infection and promotion of cell proliferation
- 2017
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Ingår i: Pathogens and Disease. - : Oxford University Press. - 2049-632X. ; 75:5
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Tidskriftsartikel (refereegranskat)abstract
- Periodontitis is a chronic inflammatory disease that is characterised by accumulation of pathogenic bacteria, including Porphyromonas gingivalis, in periodontal pockets. The lack of effective treatments has emphasised in an intense search for alternative methods to prevent bacterial colonisation and disease progression. Bacteriocins are bacterially produced antimicrobial peptides gaining increased consideration as alternatives to traditional antibiotics. We show rapid permeabilisation and aggregation of P. gingivalis by the two-peptide bacteriocin PLNC8 alpha beta. In a cell culture model, P. gingivalis was cytotoxic against gingival fibroblasts. The proteome profile of fibroblasts is severely affected by P. gingivalis, including induction of the ubiquitin-proteasome pathway. PLNC8 alpha beta enhanced the expression of growth factors and promoted cell proliferation, and suppressed proteins associated with apoptosis. PLNC8 alpha beta efficiently counteracted P. gingivalis-mediated cytotoxicity, increased expression of a large number of proteins and restored the levels of inflammatory mediators. In conclusion, we show that bacteriocin PLNC8 alpha beta displays dual effects by acting as a potent antimicrobial agent killing P. gingivalis and as a stimulatory factor promoting cell proliferation. We suggest preventive and therapeutical applications of PLNC8 alpha beta in periodontitis to supplement the host immune defence against P. gingivalis infection and support wound healing processes.
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| 4. |
- Palm, Eleonor, 1980-, et al.
(författare)
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Suppression of inflammatory responses of human gingival fibroblasts by gingipains from Porphyromonas gingivalis
- 2015
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Ingår i: Molecular Oral Microbiology. - : Wiley. - 2041-1006 .- 2041-1014. ; 30:1, s. 74-85
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Tidskriftsartikel (refereegranskat)abstract
- The interaction between human gingival fibroblasts (HGFs) and Porphyromonas gingivalis plays an important role in the development and progression of periodontitis. Porphyromonas gingivalis possesses several virulence factors, including cysteine proteases, the arginine-specific (Rgp) and lysine-specific (Kgp) gingipains. Studying the mechanisms that P.gingivalis, and its derived virulence, use to propagate and interact with host cells will increase the understanding of the development and progression of periodontitis. In this study, we aimed to elucidate how P.gingivalis influences the inflammatory events in HGFs regarding transforming growth factor-(1) (TGF-(1)), CXCL8, secretory leucocyte protease inhibitor (SLPI), c-Jun and indoleamine 2,3-dioxygenase (IDO). HGFs were inoculated for 6 and 24h with the wild-type strains ATCC 33277 and W50, two gingipain-mutants of W50 and heat-killed ATCC 33277. The P.gingivalis regulated CXCL8 and TGF-(1) in HGFs, and the kgp mutant gave significantly higher immune response with increased CXCL8 (P<0.001) and low levels of TGF-(1). We show that HGFs express and secrete SLPI, which was significantly suppressed by P.gingivalis (P<0.05). This suggests that by antagonizing SLPI, P.gingivalis contributes to the tissue destruction associated with periodontitis. Furthermore, we found that P.gingivalis inhibits the expression of the antimicrobial IDO, as well as upregulating c-Jun (P<0.05). In conclusion, P.gingivalis both triggers and suppresses the immune response in HGFs. Consequently, we suggest that the pathogenic effects of P.gingivalis, and especially the activity of the gingipains on the inflammatory and immune response of HGFs, are crucial in periodontitis.
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| 5. |
- Palm, Eleonor, 1980-, et al.
(författare)
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The role of toll-like and protease-activated receptors in the expression of cytokines by gingival fibroblasts stimulated with the periodontal pathogen Porphyromonas gingivalis
- 2015
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Ingår i: Cytokine. - : Academic Press. - 1043-4666 .- 1096-0023. ; 76:2, s. 424-432
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Tidskriftsartikel (refereegranskat)abstract
- Porphyromonas gingivalis is a periodontitis-associated pathogen and interactions between the bacterium and gingival fibroblasts play an important role in development and progression of periodontitis, an inflammatory disease leading to degeneration of tooth-supporting structures. Gingival fibroblasts, which expresses protease activated receptors (PARs) as well as toll-like receptors (TLRs), produces inflammatory mediators upon bacterial challenges. In this study, we elucidated the importance of PAR1, PAR2, TLR2 and TLR4 for the expression and secretion of CXCL8, interleukin-6 (IL-6), transforming growth factor-beta 1 (TGF-beta 1) and secretory leukocyte inhibitor (SLPI). Human gingival fibroblasts were transfected with small-interfering RNA against the target genes, and then stimulated with P. gingivalis wild-type W50 and W50-derived double rgp mutant E8 and kgp mutant K1A. TLR2-silencing reduced P. gingivalis-induced CXCL8 and IL-6. IL-6 was also reduced after PAR1-silencing. No effects were observed for TGF-beta 1. SLPI was suppressed by P. gingivalis and silencing of PAR1 as well as TLR2, gave additional suppression at the mRNA level. TLR4 was not involved in the regulation of the investigated mediators. CXCL8 and IL-6 are important for progression and development of periodontitis, leading to a chronic inflammation that may contribute to the tissue destruction that follows an exacerbated host response. Therefore, regulating the expression of TLR2 and subsequent release of CXCL8 and IL-6 in periodontitis could attenuate the tissue destruction seen in periodontitis.
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| 6. |
- Jayaprakash, Kartheyaene, 1983-, et al.
(författare)
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PKC, ERK/p38 MAP kinases and NF-B targeted signalling play a role in the expression and release of IL-1β and CXCL8 in Porphyromonas gingivalis-infected THP1 cells
- 2017
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Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : John Wiley & Sons. - 0903-4641 .- 1600-0463. ; 125:7, s. 623-633
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Tidskriftsartikel (refereegranskat)abstract
- Porphyromonas gingivalis is a keystone pathogen in periodontitis and is gaining importance in cardiovascular pathogenesis. Protease-activated receptors (PARs), toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD) on monocytes recognize the structural components on P. gingivalis, inducing inflammatory intermediates. Here, we elucidate the modulation of PARs, TLRs, NODs, and the role of MAPK and NF-B in IL-1 and CXCL8 release. THP1 cells were stimulated with P. gingivalis wild-type W50 and its isogenic gingipain mutants: Rgp mutant E8 and Kgp mutant K1A. We observed modulation of PARs, TLRs, NOD, IL-1 and CXCL8 expression by P. gingivalis. Gingipains hydrolyse IL-1 and CXCL8, which is more evident for IL-1 accumulation at 24 h. Inhibition of PKC (protein kinase C), p38 and ERK (extracellular signal-regulated kinases) partially reduced P. gingivalis-induced IL-1 at 6 h, whereas PKC and ERK reduced CXCL8 at both 6 and 24 h. Following NF-B inhibition, P. gingivalis-induced IL-1 and CXCL8 were completely suppressed to basal levels. Overall, TLRs, PARs and NOD possibly act in synergy with PKC, MAPK ERK/p38 and NF-B in P. gingivalis-induced IL-1 and CXCL8 release from THP1 cells. These pro-inflammatory cytokines could affect leucocytes in circulation and exacerbate other vascular inflammatory conditions such as atherosclerosis.
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| 7. |
- Klarström-Engström, Kristin, 1986-, et al.
(författare)
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The role of Porphyromonas gingivalis gingipains in platelet activation and innate immune modulation
- 2015
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Ingår i: Molecular Oral Microbiology. - : Wiley. - 2041-1006 .- 2041-1014. ; 30:1, s. 62-73
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Tidskriftsartikel (refereegranskat)abstract
- Platelets are considered to have important functions in inflammatory processes and as actors in the innate immunity. Several studies have shown associations between cardiovascular disease and periodontitis, where the oral anaerobic pathogen Porphyromonas gingivalis has a prominent role in modulating the immune response. Porphyromonas gingivalis has been found in atherosclerotic plaques, indicating spreading of the pathogen via the circulation, with an ability to interact with and activate platelets via e.g. Toll-like receptors (TLR) and protease-activated receptors. We aimed to evaluate how the cysteine proteases, gingipains, of P.gingivalis affect platelets in terms of activation and chemokine secretion, and to further investigate the mechanisms of platelet-bacteria interaction. This study shows that primary features of platelet activation, i.e. changes in intracellular free calcium and aggregation, are affected by P.gingivalis and that arg-gingipains are of great importance for the ability of the bacterium to activate platelets. The P.gingivalis induced a release of the chemokine RANTES, however, to a much lower extent compared with the TLR2/1-agonist Pam(3)CSK(4), which evoked a time-dependent release of the chemokine. Interestingly, the TLR2/1-evoked response was abolished by a following addition of viable P.gingivalis wild-types and gingipain mutants, showing that both Rgp and Kgp cleave the secreted chemokine. We also demonstrate that Pam(3)CSK(4)-stimulated platelets release migration inhibitory factor and plasminogen activator inhibitor-1, and that also these responses were antagonized by P.gingivalis. These results supports immune-modulatory activities of P.gingivalis and further clarify platelets as active players in innate immunity and in sensing bacterial infections, and as target cells in inflammatory reactions induced by P.gingivalis infection.
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| 8. |
- Jayaprakash, Kartheyaene, et al.
(författare)
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Porphyromonas gingivalis-induced inflammatory responses in THP1 cells are altered by native and modified low-density lipoproteins in a strain-dependent manner
- 2018
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Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley-Blackwell Publishing Inc.. - 0903-4641 .- 1600-0463. ; 126:8, s. 667-677
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Tidskriftsartikel (refereegranskat)abstract
- Strong epidemiological evidence supports an association between cardiovascular and periodontal disease and furthermore, the periodontopathogen Porphyromonas gingivalis has been identified in blood and from atheromatous plaques. Blood exposed to P.gingivalis shows an increased protein modification of low-density lipoprotein (LDL). In this study, we investigate the inflammatory responses of THP1 cells incubated with P.gingivalis and the effects of native or modified LDL on these responses. Reactive oxygen species (ROS) and IL-1 were observed in THP1 cells following infection with P.gingivalis ATCC33277 and W50. Caspase 1 activity was quantified in THP1 cells and correlated with IL-1 accumulation. Oxidized LDL (oxLDL) induced IL-1 release and CD36 expression on THP1 cells. Modified LDL co-stimulated with ATCC33277 exhibited regulatory effects on caspase 1 activity, IL-1 release and CD36 expression in THP1 cells, whereas W50 induced more modest responses in THP1 cells. In summary, we show that P.gingivalis is capable of inducing pro-inflammatory responses in THP1 cells, and native and modified LDL could alter these responses in a dose- and strain-dependent manner. Strain-dependent differences in THP1 cell responses could be due to the effect of P.gingivalis proteases, presence or absence of capsule and proteolytic transformation of native and modified LDL.
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| 9. |
- Musa, Amani, 1983-, et al.
(författare)
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Plantaricin NC8 alpha beta prevents Staphylococcus aureus-mediated cytotoxicity and inflammatory responses of human keratinocytes
- 2021
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Ingår i: Scientific Reports. - : Nature Portfolio. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Multidrug resistance bacteria constitue an increasing global health problem and the development of novel therapeutic strategies to face this challenge is urgent. Antimicrobial peptides have been proven as potent agents against pathogenic bacteria shown by promising in vitro results. The aim of this study was to characterize the antimicrobial effects of PLNC8 alpha beta on cell signaling pathways and inflammatory responses of human keratinocytes infected with S. aureus. PLNC8 alpha beta did not affect the viability of human keratinocytes but upregulated several cytokines (IL-1 beta, IL-6, CXCL8), MMPs (MMP1, MMP2, MMP9, MMP10) and growth factors (VEGF and PDGF-AA), which are essential in cell regeneration. S. aureus induced the expression of several inflammatory mediators at the gene and protein level and PLNC8 alpha beta was able to significantly suppress these effects. Intracellular signaling events involved primarily c-Jun via JNK, c-Fos and NF kappa B, suggesting their essential role in the initiation of inflammatory responses in human keratinocytes. PLNC8 alpha beta was shown to modulate early keratinocyte responses, without affecting their viability. The peptides have high selectivity towards S. aureus and were efficient at eliminating the bacteria and counteracting their inflammatory and cytotoxic effects, alone and in combination with low concentrations of gentamicin. We propose that PLNC8 alpha beta may be developed to combat infections caused by Staphylococcus spp.
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| 10. |
- Svärd, Anna, 1985-, et al.
(författare)
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Protein-Functionalized Gold Nanoparticles as Refractometric Nanoplasmonic Sensors for the Detection of Proteolytic Activity of Porphyromonas gingivalis
- 2020
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society. - 2574-0970. ; 3:10, s. 9822-9830
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Tidskriftsartikel (refereegranskat)abstract
- Periodontitis is an inflammatory oral disease that affects a large part of the adult population, causing significant costs and suffering. The key pathogen, Porphyromonas gingivalis, secretes gingipains, which are highly destructive proteases and the most important virulence factors in the pathogenesis of the disease. Currently, periodontitis is diagnosed mainly by mechanical manual probing and radiography, often when the disease has already progressed significantly. The possibilities of detecting gingipain activity in gingival fluid could enable early-stage diagnosis and facilitate treatment. Here, we describe a sensitive nanoparticle-based nanoplasmonic biosensor for the detection of the proteolytic activity of gingipains. Gold nanoparticles (AuNPs) were self-assembled as a submonolayer in multiwell plates and further modified with casein or IgG. The proteolytic degradation of the protein coating was tracked by monitoring the shift in the localized surface plasmon resonance (LSPR) peak position. The sensor performance was investigated using model systems with trypsin and purified gingipains (subtypes Kgp and RgpB) and further validated using supernatants from cultures of P. gingivalis. Proteolytic degradation by proteases in buffer results in a concentration- and time-dependent blueshift of the LSPR band of about 1-2 nm when using casein as a substrate. In bacterial supernatants, the degradation of the protein coating resulted in unspecific binding of proteins present in the complex sample matrix to the nanoparticles, which instead triggered a redshift of about 2 nm of the LSPR band. A significant LSPR shift was seen only in samples with gingipain activity. The sensor showed a limit of detection < 0.1 mu g/mL (4.3 nM), which is well below gingipain concentrations detected in severe chronic periodontitis cases (similar to 50 mu g/mL). This work shows the possibility of developing cost-effective nanoparticle-based biosensors for rapid detection of protease activity for chair-side periodontal diagnostics.
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