[Show abstract][Hide abstract] ABSTRACT: Arbidol is an antiviral drug that have broad-spectrum activity against a number of viral infections. To date, there is no specific data regarding its effects against a herpesvirus. Here the in vitro antiviral effect of ARB and structurally related derivatives were evaluated in HaCat cells on different steps of HSV1 replication: adsorption, entry and post-entry. The simplified pyrrolidine analogue 9a2, showed the best antiviral activity in vitro by reducing the plaque numbers by about 50%, instead of 42% obtained with Arbidol at the same concentration. Furthermore, we have reported that all tested compounds, evaluated for their immunomodulatory activity, showed the ability to reduce the viral protein VP16 and ICP27 and to modify the virus-induced cytokines expression, allowing the host cell a more efficient antiviral response.
Full-text · Article · Sep 2014 · Journal of Medical Microbiology
[Show abstract][Hide abstract] ABSTRACT: Background
Vaginal lactic acid bacteria defend the host against pathogens through a combination of competitive exclusion, competition for nutrients, production of antimicrobial substances and through the activation of the immune system. A new human isolate named Lactobacillus crispatus L1 was characterized in this work, and a preliminary evaluation of its probiotic potential is described together with a process to obtain a high productivity of viable biomass.
In a simulated digestion process 1.8⋅1010 cells∙ml−1 survived the gastric environment with 80% viability, without being affected by small intestine juices. Experiments on six different C sources were performed to analyze growth and organic acids production and, glucose, provided the best performances. A microfiltration strategy was exploited to improve the cellular yield in 2 L-fermentation processes, reaching 27 g · l−1 of dry biomass. Moreover, L. crispatus L1 demonstrated a greater stability to high concentrations of lactic acid, compared to other lactobacilli. The specific L. crispatus L1 exopolysaccharide was purified from the fermentation broth and characterized by NMR showing structural features and similarity to exopolysaccharides produced by pathogenic strains. Live L. crispatus L1 cells strongly reduced adhesion of a yeast pathogenic strain, Candida albicans in particular, in adherence assays. Interestingly a higher expression of the human defensin HBD-2 was also observed in vaginal cells treated with the purified exopolysaccharide, indicating a possible correlation with C. albicans growth inhibition.
The paper describes the evaluation of L. crispatus L1 as potential vaginal probiotic and the fermentation processes to obtain high concentrations of viable cells.
[Show abstract][Hide abstract] ABSTRACT: Topical immunosuppressant therapy is widely used in the treatment of inflammatory skin diseases, such as atopic dermatitis and psoriasis. Besides its beneficial therapeutic effects, application of topical anti-inflammatory drugs may render the epidermis more vulnerable to invading pathogens by suppressing innate immune responses in keratinocytes (KCs). Cytokines, chemokines and antimicrobial peptides (AMPs) produced by epithelial cells enable them to participate in innate and acquired immune responses. The aim of the present work was to study the influence of tacrolimus (FK506) on KCs infected with Malassezia furfur (M. furfur), evaluating the expression of pro-inflammatory cytokines IL-1α and IL-6, chemokine IL-8, anti-inflammatory cytokines transforming growth factor beta1 (TGF-β1) and IL-10 and AMP β-defensin-2. Human KCs were obtained from surgical specimens of normal adult skin. The expression of mRNAs in KCs: FK506-treated, FK506-treated and M. furfur-infected as well as only M. furfur-infected was quantified by real-time quantitative polymerase chain reaction. Next, the production of the AMP β-defensin-2 and of the above-mentioned pro-inflammatory and anti-inflammatory cytokines was evaluated using enzyme-linked immunosorbent assay. In this study, FK506 did not alter cytokine and AMP production by KCs; this led us to hypothesise that it may not enhance the risk of mycotic skin infections.
[Show abstract][Hide abstract] ABSTRACT: Interaction of pathogenic bacteria with human cells is usually an essential step in the infection process. The bacterial invasion is stimulated by microbial binding to mammalian extracellular matrix proteins such as vitronectin, fibronectin or integrins. We have recently shown that some strains isolated from a clinical environment are able to grow at/or above 37°C. In particular, we demonstrated that P. fluorescens AF181 binds specifically to the surface of A549 human respiratory epithelial cells and that adhesiveness modulates the inflammatory response. In this study, the involvement of AlphaᵥBeta₅ integrins and its respective natural ligand vitronectin (VN) in P. fluorescens AF181 adherence and invasion was examined. The host cell cytoskeleton and cellular tyrosine kinases seem to be solicited during the P. fluorescens-respiratory cell interaction; consequently, cytochalasin D and genistein decreased the bacterial adherence and internalization. Gene silencing of αᵥ, β₅ integrins and vitronectin reduced P. fluorescens adherence and internalization to A549 cells. Taken together, these findings suggest that AlphaᵥBeta₅ integrins and their natural ligand VN are involved in P. fluorescens adherence and invasion in human epithelial cells.
Full-text · Article · Jan 2014 · Frontiers in Bioscience
[Show abstract][Hide abstract] ABSTRACT: Oral candisosis is an heterogeneous group of diseases, caused by different species of Candida fungus. The incidence of drug-resistant species is increasing dramatically; furthermore, in recent years higher incidences of non-albicans and antimycotic-resistant species of Candida have been reported, thus increasing necessity of a non-antibiotic agent, which should be both highly effective and safe. It has been showed that the main polyphenolic component of green tea, epigallocatechin-gallate (EGCG), has antibacterial activity; recently, it has been reported its antifungal activity too. We tested the effectiveness of a 0.20% EGCG (TEAVIGO ®) gel, a non-pharmaceutical product suitable for oral in vivo use, on four species of Candida yeast (C.albicans, C.parapsilosis, C.tropicalis, C.glabrata), evaluating its antifungal activity and its capacity to inhibit biofilm formation. The EGCG gel showed a remarkable activity against C. parapsilosis and C. tropicalis. This preliminary study confirms EGCG effectiveness on fungi; for this reason, a product with such a low concentration of EGCG could be used with no side-effect for every-day oral hygiene. Anyway, mechanisms of antifungal activity of EGCG are not comprehended and need further studies to better understand the reasons of some Candida species' resistance.
[Show abstract][Hide abstract] ABSTRACT: Peptide T (PT), an octapeptide fragment located in the V2 region of the HIV-1 gp120-coating protein, appears to be beneficial in the treatment of psoriasis. Our previous investigations suggest that keratinocytes play a key role in conditioning the therapeutic effects of PT in psoriasis. The aim of this study was to explore the effects of PT and the peptidomimetic natural products, Dhurrin and Prunasin, on the expression of the IL-6, IL-8, IL-23, HSP70 and ICAM-1 on IFN-γ and TNF-α-NHEK activated cells. Moreover, we analysed the interference of PT and its analogues through STAT-3 activation. Our results show that the analogues tested exhibit the beneficial biological effects of PT, suggesting the primary role of keratinocytes upon which PT and the peptidomimetics act directly, by reducing proinflammatory responses. Its reduction appears to be important for therapeutic approach in psoriasis pathogenesis.
[Show abstract][Hide abstract] ABSTRACT: Chromium and nickel cause allergic contact dermatitis, a common biological skin response to sensitizing agents. This study used a conventional in vitro wounding model to study the impact of sensitizing agents on the innate immune response of human keratinocytes. Experiments were designed to evaluate the involvement of specific Toll-like receptors and metalloproteinases as effectors molecules downstream, at a molecular level. Further, keratinocytes were co-cultured with monocytes (THP-1 cells) to reproduce an inductive stimulus on monocytes made by metals. Human keratinocytes (HaCat) were grown on plates covered with collagen type I, chemically treated, and then mechanically injured with a sterile pipette tip. Restoration of the monolayer integrity was monitored by time-lapse video microscopy. Effector gene expression was evaluated by real-time PCR. The presence of chromium significantly dropped the rate of wound closure, while nickel-induced hyper-proliferation ended in an acceleration of the healing process, an event that does not occur in vivo. This latter outcome led to considering nickel as an unsuitable example for use in the experimental model. Focusing solely on the chromium aspect of this study, RNA profiles of selected molecular markers were generated to ascertain if the detrimental stimulus from chromium was eliminated or persisted both in keratinocytes alone and/or during co-cultures of keratinocytes and monocytes. Monocytes accelerated the process of wound repair. This in vitro experimental model highlighted the involvement of innate immunity in response to chromium and might be useful for test molecules of therapeutic interest for the treatment of skin lesions. However, the experience with nickel reveals that there are limitations to the utility of this wound model system after all.
No preview · Article · May 2012 · Journal of Immunotoxicology
[Show abstract][Hide abstract] ABSTRACT: The most important function of the skin is the formation of a barrier between the "inside" and the "outside" of the organism, which prevents invasion of pathogens and fends off chemical assaults as well as the unregulated loss of water and solutes. The physical barrier is mainly localized in the stratum corneum, which consists of protein-enriched cells and lipid-enriched intercellular domains. Any modifications in epidermal differentiation and lipid composition results in altered barrier function, a central event in various skin alterations and diseases. This contribution presents a brief description of the structure of the skin, paying attention to the most important components responsible for skin barrier function.
Full-text · Article · May 2012 · Clinics in dermatology
[Show abstract][Hide abstract] ABSTRACT: Photodynamic therapy (PDT) is a selective modality of killing targeted cells, mostly known for its application in neoplasms. PDT can be considered to be an alternative method for the elimination of periodontal bacteria from the pocket without harms for the resident tissues. Therefore, PDT may replace systemic antibiotics and enhance the effect of mechanical treatments of periodontal defects. This effort focused on the in vitro sensitization of periopathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Fusobacterium nucleatum and Prevotella intermedia ) Toluidine Blue mediated and on the use of a Diode laser emitting source. The objective of this research was to evaluate the bactericidal in vitro effect of laser diodes 830 nm (as the light source) after photosensitization with Toluidine Blue (TBO) on the following periopathogenic bacteria: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Fusobacterium nucleatum and Prevotella intermedia. After evaluating the effect on the single bacterial strain, the ability of Diode Laser to disrupt the structure of biofilms produced by A. actinomycetemcomitans after photosensitization with TBO was also analyzed. The study suggests that the association of TBO and diode laser light 830 nm is effective for the killing of bacteria strains and determines the photoinactivation of Aggregatibacter biofilms. In summary, photodynamic therapy has effectively shown its capabilities and, therefore, it can be considered a valid alternative approach to antimicrobial therapy of periodontitis.
Full-text · Article · Oct 2010 · International journal of immunopathology and pharmacology
[Show abstract][Hide abstract] ABSTRACT: Herpes labialis are the most frequent clinical manifestations of HSV-1 infection. Epithelial cells are able to respond to HSV-1 presence inducing the expression of IL-6, IL-1, TNF-α and IL-8. These proinflammatory cytokines have a function in the acute-phase response mediation, chemotaxis, inflammatory cell activation and antigen-presenting cells. In the human epithelial cell models, it has been demonstrated that, after an early induction of proinflammatory host response, HSV-1 down-modulates the proinflammatory cytokine production through the accumulation of two viral proteins, ICP4 and ICP27, whose transcription is induced by tegument protein VP16. These viral proteins, through the decreasing of stabilizing the mRNAs of proinflammatory genes, delay cytokine production to an extent that allows the virus to replicate. Moreover, viral transactivating proteins, ICP-0 and VP-16 induce IL-10 expression. The conventional treatment of herpes labialis involves the topical and systemic use of antiviral drugs but it is necessary to find new therapies that can act in a selective and non-cytotoxic manner in viral infection. Laser diode therapy has been considered as a non-invasive alternative treatment to the conventional treatment of herpes labialis in pain therapy, in modulation of inflammation and in wound healing. This study aims to report a possible mechanism of action of laser diode irradiation in prevention and reduction of severity of labial manifestations of herpes labialis virus. We investigated, in an in vitro model of epithelial cells HaCat, the laser-effect on HSV-1 replication and we evaluated the modulation of expression of certain proinflammatory cytokines (TNF-α, IL-1β and IL-6), antimicrobial peptide HBD2, chemokine IL-8 and the immunosuppressive cytokine, IL-10. Our results lead us to hypothesize that LD-irradiation acts in the final stage of HSV-1 replication by limiting viral spread from cell to cell and that laser therapy acts also on the host immune response unblocking the suppression of proinflammatory mediators induced by accumulation of progeny virus in infected epithelial cells.
Full-text · Article · Oct 2010 · International journal of immunopathology and pharmacology