[Show abstract][Hide abstract] ABSTRACT: Herpes simplex virus type 1 (HSV-1) and HSV-2 are neurotropic viruses and common human pathogens causing major public health problems such as genital herpes, a sexually transmitted disease also correlated with increased transmission and replication of human immunodeficiency virus type 1 (HIV-1). Therefore, compounds capable of blocking HIV-1, HSV-1, and HSV-2 transmission represent candidate microbicides with a potential added value over that of molecules acting selectively against either infection. We report here that sulfated derivatives of the Escherichia coli K5 polysaccharide, structurally highly similar to heparin and previously shown to inhibit HIV-1 entry and replication in vitro, also exert suppressive activities against both HSV-1 and HSV-2 infections. In particular, the N,O-sulfated [K5-N,OS(H)] and O-sulfated epimerized [Epi-K5-OS(H)] forms inhibited the infection of Vero cells by HSV-1 and -2, with 50% inhibitory concentrations (IC(50)) between 3 +/- 0.05 and 48 +/- 27 nM, and were not toxic to the cells at concentrations as high as 5 muM. These compounds impaired the early steps of HSV-1 and HSV-2 virion attachment and entry into host cells and reduced the cell-to-cell spread of HSV-2. Since K5-N,OS(H) and Epi-K5-OS(H) also inhibit HIV-1 infection, they may represent valid candidates for development as topical microbicides preventing sexual transmission of HIV-1, HSV-1, and HSV-2.
[Show abstract][Hide abstract] ABSTRACT: A novel human coronavirus causing severe acute respiratory syndrome (SARS) emerged in epidemic form in early 2003 in China and spread worldwide in a few months. Every newly emerging human pathogen is of concern for the safety of the blood supply during and after an epidemic crisis. For this purpose, we have evaluated the inactivation of SARS-coronavirus (CoV) in platelet concentrates using an approved pathogen inactivation device, the INTERCEPT Blood System. Apheresis platelet concentrates (APCs) were inoculated with approximately 10(6) pfu mL(-1) of either Urbani or HSR1 isolates of SARS-CoV. The inoculated units were mixed with 150 microm amotosalen and illuminated with 3 J cm(-2) UV-A light. The viral titres were determined by plaque formation in Vero E6 cells. Mixing SARS-CoV with APC in the absence of any treatment decreased viral infectivity by approximately 0.5-1 log10. Following photochemical treatment, SARS-CoV was consistently inactivated to the limit of detection in seven independent APC units. No infectious virus was detected after treatment when up to one-third of the APC unit was assayed, demonstrating a mean log10-reduction of >6.2. Potent inactivation of SARS-CoV therefore extends the capability of the INTERCEPT Blood System in inactivating a broad spectrum of human pathogens including recently emerging respiratory viruses.
Transfusion Medicine 09/2005; 15(4):269-76. DOI:10.1111/j.0958-7578.2005.00588.x · 1.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: There is currently an urgent need to identify effective antiviral agents that will prevent and treat severe acute respiratory syndrome coronavirus (SARS-CoV) infection. In this study, we have investigated and compared the antiviral effect of different interferons (IFNs) on SARS-CoV replication in the epithelial kidney monkey Vero cell line. The results showed that SARS-CoV grown in Vero cells is moderately sensitive to IFN-beta and only weakly sensitive to IFN-alpha and IFN-gamma, in comparison to other IFN-sensitive viruses, such as those for encephalomyocarditis, vesicular stomatitis and Newcastle disease. Simultaneous incubation of Vero cells with IFN-beta and IFN-gamma indicated that they may act synergistically against SARS-CoV replication. The IFN-induced MxA protein was detected in the IFN-treated Vero cells. The data, however, suggest that the antiviral activity of IFN against SARS-CoV virus is independent of MxA expression.
[Show abstract][Hide abstract] ABSTRACT: The ideal microbicide must fulfill a number of criteria including a broad and potent activity against transmission of HIV and other sexually transmitted agents in the absence of toxicity and inflammation. We have described that derivatives of K5 polysaccharide from Escherichia coli inhibit HIV entry in target cells. K5 derivatives have a structure that resembles that of heparin, but they are devoid of the anticoagulant activity typical of heparin. Moreover, in contrast to heparin, they inhibit a broad spectrum of HIV-1 laboratory-adapted and primary isolates that use either CCR5 or CXCR4 or both coreceptors in terms of their infection and replication in primary CD4+ lymphocytes and monocytes-derived macrophages (MDM). Therefore, these compounds could be developed as candidate microbicides for preventing sexual HIV transmission, a predominant modality of HIV spreading in both the developed and underdeveloped world.
The New Microbiologica: official journal of the Italian Society for Medical Virology (SIVIM) 05/2004; 27(2 Suppl 1):5-9. · 1.60 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: During the recent severe acute respiratory (SARS) outbreak, the etiologic agent was identified as a new coronavirus (CoV). We have isolated a SARS-associated CoV (SARS-CoV) strain by injecting Vero cells with a sputum specimen from an Italian patient affected by a severe pneumonia; the patient traveled from Vietnam to Italy in March 2003. Ultrastructural analysis of infected Vero cells showed the virions within cell vesicles and around the cell membrane. The full-length viral genome sequence was similar to those derived from the Hong-Kong Hotel M isolate. By using both real-time reverse transcription-polymerase chain reaction TaqMan assay and an infectivity plaque assay, we determined that approximately 360 viral genomes were required to generate a PFU. In addition, heparin (100 microg/mL) inhibited infection of Vero cells by 50%. Overall, the molecular and biologic characteristics of the strain HSR1 provide evidence that SARS-CoV forms a fourth genetic coronavirus group with distinct genomic and biologic features.
[Show abstract][Hide abstract] ABSTRACT: Two different prime-boost immunization protocols were tested in rabbits and their immune response was evaluated and compared with the final aim of defining a vaccine strategy that might be able to protect non-human primates from infection with the pathogenic simian/human immunodeficiency virus, SHIV(89.6P). The two regimens were based on three priming immunizations with either an expression plasmid plus a fowlpox (FP) recombinant vector or with two FP recombinant vectors, each one expressing either the SIV(mac239) gag/pol or the HIV-1env(89.6P) genes. In both protocols, priming immunizations were followed by two boosts with SHIV-mimicking virus-like particles (VLP). A complete SHIV-specific response was observed in all animals. Interestingly, the DNA vaccine was three to 10 times more efficient than the FP recombinant in inducing an anti-gag humoral response. Real-time PCR confirmed the memory effect on T-cell subsets secreting interleukin-4 and interferon-gamma, as a consequence of stimulation of both arms of the immune system. Although both protocols were almost equally effective in eliciting homologous neutralizing antibodies and highlighted the efficacy of VLP administration for boosting, protocol A seemed to be more effective in promoting a balanced T-cell memory immune response and appears more promising for vaccine purposes.