654 research outputs found

    Bioactive Molecules Released From Cells Infected with the Human Cytomegalovirus.

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    Following primary infection in humans, the Human Cytomegalovirus (HCMV) persists in a latent state throughout the host’s lifetime despite a strong and efficient immune response. If the host experiences some form of immune dysregulation, such as immunosuppression or immunodeficiency, HCMV reactivates, thereby emerging from latency. Thus, in the absence of effective functional immune responses, as occurs in immunocompromised or immunoimmature individuals, both HCMV primary infections and reactivations from latency can cause significant morbidity and mortality. However, even in immunocompetent hosts, HCMV represents a relevant risk factor for the development of several chronic inflammatory diseases and certain forms of neoplasia. HCMV infection may shift between the lytic and latent state, regulated by a delicate and intricate balance between virus-mediated immunomodulation and host immune defenses. Indeed, HCMV is a master in manipulating innate and adaptive host defense pathways, and a large portion of its genome is devoted to encoding immunomodulatory proteins; such proteins may thus represent important virulence determinants. However, the pathogenesis of HCMV-related diseases is strengthened by the activities of bioactive molecules, of both viral and cellular origin, that are secreted from infected cells and collectively named as the secretome. Here, we review the state of knowledge on the composition and functions of HCMV-derived secretomes. In lytic infections of fibroblasts and different types of endothelial cells, the majority of HCMV-induced secreted proteins act in a paracrine fashion to stimulate the generation of an inflammatory microenvironment around infected cells; this may lead to vascular inflammation and angiogenesis that, in turn, foster HCMV replication and its dissemination through host tissues. Conversely, the HCMV secretome derived from latently infected hematopoietic progenitor cells induces an immunosuppressive extracellular environment that interferes with immune recognition and elimination of latently infected cells, thereby promoting viral persistence. Characterization of the composition and biological activities of HCMV secretomes from different types of infected cells will lay the foundation for future advances in our knowledge about the pathogenesis HCMV diseases and may provide targets for the development of novel antiviral intervention strategies

    Inhibition of herpes simplex type 1 and type 2 infections by Oximacro®, a cranberry extract with a high content of A-type proanthocyanidins (PACs-A)

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    AbstractIn the absence of efficient preventive vaccines, topical microbicides offer an attractive alternative in the prevention of Herpes simplex type 1 (HSV-1) and type 2 (HSV-2) infections. Because of their recognized anti-adhesive activity against bacterial pathogens, cranberry (Vaccinium macrocarpon Ait.) extracts may represent a natural source of new antiviral microbicides. However, few studies have addressed the applications of cranberry extract as a direct-acting antiviral agent. Here, we report on the ability of the novel cranberry extract Oximacro® and its purified A-type proanthocyanidins (PACs-A), to inhibit HSV-1 and HSV-2 replication in vitro. Analysis of the mode of action revealed that Oximacro® prevents adsorption of HSV-1 and HSV-2 to target cells. Further mechanistic studies confirmed that Oximacro® and its PACs-A target the viral envelope glycoproteins gD and gB, thus resulting in the loss of infectivity of HSV particles. Moreover, Oximacro® completely retained its anti-HSV activity even at acidic pHs (3.0 and 4.0) and in the presence of 10% human serum proteins; conditions that mimic the physiological properties of the vagina - a potential therapeutic location for Oximacro®.Taken together, these findings indicate Oximacro® as an attractive candidate for the development of novel microbicides of natural origin for the prevention of HSV infections

    Nucleic Acid Sequence-Based Amplification using molecular beacons for quantification of enterovirus RNA

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    Quantificazione dell'enterovirus RNA mediante Nucleic Acid Sequence-Based Amplification utilizzando sonde molecular beacon

    Polyomavirus BK replication in renal transplant recipients: combined monitoring of viremia and VP1 mRNA in urine

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    Introduction. Human polyomavirus BK (BKV) is worldwide distributed, with a seroprevalence rate of 70–90% in the adults. Following primary infection, BK remains latent in the renourinary tract as the epidemiologically most relevant latency site, and in B cell, brain, spleen and probably other tissues. Reactivation may occur in both immunocompetent subjects and immunocompromised patients. In renal transplantation, in the context of intense immunosuppression, viral replication may determine BKV-associated nephropathy (BKVAN) with interstitial nephritis and/or ureteral stenosis in 1–10% of the patients and leading to graft failure and return to haemodialysis in 30 to 80% of the cases (5). Screening of BKV replication represents the basic strategy to predict early the onset of BKVAN and may allow for earlier intervention with reduced allograft loss (3, 4). Nowadays, replication of BKV is monitored by quantification of BKV-DNA in serum and urine (2). The aim of this study was to evaluated the role of BKV VP1 mRNA in urine as a marker of viral replication in renal transplant recipients
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