West Nile Virus Infections in (European) Birds

West Nile virus (WNV), a member of the Flaviviridae family is an important emerging pathogen transmitted by mosquitoes of the Culex sp . wild-and (peri) domesticated birds act as the natural hosts of WNV. Birds are not only susceptible to WNV, but also participate in maintaining the transmission cycle

Genome editing technologies to fight infectious diseases

Genome editing by programmable nucleases represents a promising tool that could be exploited to develop new therapeutic strategies to fight infectious diseases. These nucleases, such as zinc-finger nucleases, transcription activator-like effector nucleases, clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated protein 9 (Cas9) and homing endonucleases, are molecular scissors that can be targeted at predetermined loci in order to modify the genome sequence of an organism. Areas covered: By perturbing genomic DNA at predetermined loci, programmable nucleases can be used as antiviral and antimicrobial treatment. This approach includes targeting of essential viral genes or viral sequences able, once mutated, to inhibit viral replication; repurposing of CRISPR-Cas9 system for lethal self-targeting of bacteria; targeting antibiotic-resistance and virulence genes in bacteria, fungi, and parasites; engineering arthropod vectors to prevent vector-borne infections. Expert commentary: While progress has been done in demonstrating the feasibility of using genome editing as antimicrobial strategy, there are still many hurdles to overcome, such as the risk of off-target mutations, the raising of escape mutants, and the inefficiency of delivery methods, before translating results from preclinical studies into clinical applications

Zika virus infection in semen: Effect on human reproduction

Unique among vector-borne flaviviruses, Zika virus can infect testis and male genital tract, can persist in semen for months after symptoms onset, and be sexually transmitted. In The Lancet Infectious Diseases, Guillaume Joguet and colleagues report alterations of sperm and testicular function in men with Zika virus infection, with potential effect on human reproduction. In this prospective longitudinal study, the authors detected viral RNA in the semen of 11 of 15 tested men, including five with persistent seminal shedding after viral clearance in blood. Notably, they were able to isolate infectious virus from motile spermatozoa obtained using semen separation methods that are generally used in assisted reproductive procedures. Semen alterations were observed, including a decreased sperm count and a concurrent increment of multiple sperm anomalies, especially in patients with Zika virus RNA-positive seminal specimens, while recovery was observed at day 120 post infection. In addition, inhibin \u3b2 concentrations decreased after infection, suggesting an impairment of Sertoli cells, which are key components of the blood\u2013testis barrier, produce immunoregulatory factors, and provide support to sperm cells during spermatogenesis. These findings suggest a direct effect of viral infection on the testis or epididymis with impairment of sperm development, in agreement with findings in animal models

Recombinant Envelope-Proteins with Mutations in the Conserved Fusion Loop Allow Specific Serological Diagnosis of Dengue-Infections

Dengue virus (DENV) is a mosquito-borne flavivirus and a major international public health concern in many tropical and sub-tropical areas worldwide. DENV is divided into four major serotypes, and infection with one serotype leads to immunity against the same, but not the other serotypes. The specific diagnosis of DENV-infections via antibody-detection is problematic due to the high degree of cross-reactivity displayed by antibodies against related flaviviruses, such as West Nile virus (WNV), Yellow Fever virus (YFV) or Tick-borne encephalitis virus (TBEV). Especially in areas where several flaviviruses co-circulate or in the context of vaccination e.g. against YFV or TBEV, this severely complicates diagnosis and surveillance. Most flavivirus cross-reactive antibodies are produced against the highly conserved fusion loop (FL) domain in the viral envelope (E) protein. We generated insect-cell derived recombinant E-proteins of the four DENV-serotypes which contain point mutations in the FL domain. By using specific mixtures of these mutant antigens, cross-reactivity against heterologous flaviviruses was strongly reduced, enabling sensitive and specific diagnosis of the DENV-infected serum samples in IgG and IgM-measurements. These results have indications for the development of serological DENV-tests with improved specificity

Modeling viral infectious diseases and development of antiviral therapies using human induced pluripotent stem cell-derived systems

The recent biotechnology breakthrough of cell reprogramming and generation of induced pluripotent stem cells (iPSCs), which has revolutionized the approaches to study the mechanisms of human diseases and to test new drugs, can be exploited to generate patient-specific models for the investigation of host-pathogen interactions and to develop new antimicrobial and antiviral therapies. Applications of iPSC technology to the study of viral infections in humans have included in vitro modeling of viral infections of neural, liver, and cardiac cells; modeling of human genetic susceptibility to severe viral infectious diseases, such as encephalitis and severe influenza; genetic engineering and genome editing of patient-specific iPSC-derived cells to confer antiviral resistance

Human Papillomavirus Type Distribution and Correlation with Cyto-Histological Patterns in Women from the South of Italy

Human papillomavirus (HPV) type-specific distribution was evaluated in genital samples collected from 654 women from the South of Italy undergoing voluntary screening and correlated with cyto-histological abnormalities. HPV DNA was detected in 45.9% of the samples, 41.7% of which had multiple infection and 89.0% had high-risk HPV infection. The prevalence of HPV infection and the rate of multiple infections decreased with age, suggesting natural selection of HPV types with better fitness. In line with other Italian studies, the most common HPV types were HPV-6 and HPV-16, followed by HPV-51, HPV-31, HPV-53, and HPV-66, in women with both normal and abnormal cytology. Cervical intraepithelial lesions grade 2 or 3 were associated with high-risk HPV-16, HPV-18, HPV-31, and HPV-51 infection. These data indicate that prophylactic HPV vaccination is expected to reduce the burden of HPV-related cervical lesions in this population, but also suggest the potential utility of new vaccines with larger type coverage

West Nile virus infection in individuals with pre-existing Usutu virus immunity, northern Italy, 2018

In 2018, there was a large West Nile virus (WNV) outbreak in northern Italy. We observed five atypical cases of WNV infection that were characterised by the presence of WNV RNA and WNV IgG at the time of diagnosis, but no IgM response during follow-up. Neutralisation assays demonstrated pre-existing Usutu virus immunity in all patients. Besides challenging diagnosis, the immunological crosstalk between the two viruses warrants further investigation on possible cross-protection or infection enhancement effects

126. Evaluation of Replication Competent and Replication Incompetent Adenovirus-Mediated Toxicity in Human Adrenocortical Cells

Objectives: Experimental studies indicate that adenoviruses have a natural tropism for the adrenal gland, thus, the systemic use of adenoviral vectors might be associated with side effects due to adrenal gland infection. In this study, human ACC cells were used to assess the toxicity of replication competent adenovirus type 5 (Ad5) and replication deficient E1-/E3- adenoviral vectors. Methods: To test the susceptibility of human ACC cells (SW13 and NCI-H295R) to adenoviral infection, expression of coxsackie and adenovirus receptor(CAR) and integrins was evaluated in ACC cells as well as in normal human adrenocortical tissues and in benign and malignant adrenocortical tumor samples by quantitative real-time RT-PCR. ACC cells were infected with Ad5 and tested for virus production at different time points pi. Recombinant E1-/E3- Ad5 vector expressing green fluorescent protein (Ad5-EGFP) was used to test adenovirus infectivity by fluorescent microscopy and FACS analysis. To assess the toxicity of replication competent and replication incompetent adenoviral vectors in the adrenal gland, Ad5, Ad5-EGFP and Ad5-HSV-TK were employed. In this regard, at different time points pi, we examined the effect of adenoviral infection on gene expression profile by DNA microarray analysis and on cell growth by proliferation assay, cell cycle analysis, and apoptosis test. The influence of adenoviral infection on steroid hormone production was also analyzed. Results: CAR expression was demonstrated in ACC cells and in normal and neoplastic adrenocortical tissues. Both ACC cells demonstrated productive Ad5 replication and efficient Ad5-EGFP transduction. Time- and dose-dependent induction of cell death was found only in Ad5-infected ACC cells, whereas Ad5- EGFP and Ad5-HSV-TK had no apparent effect on cell proliferation, cell cycle, and cell death as compared to uninfected control. ACC cells did not show marked alterations of gene expression after Ad5-EGFP infection, as demonstrated by microarray analysis in time course infection experiments. In the early phase of infection, genes involved in cell proliferation, stress and innate immune response were transiently upregulated. Moreover, expression of genes encoding steroidogenic enzymes was modulated toward cortisol hypersecretion. With regard to steroidogenesis, ACC cells infected with Ad5 showed decreased basal steroid hormone production in the early phase pi, followed by increased steroid hormone release at 72 h pi. At variance, Ad5-EGFP markedly induced cortisol and estradiol production, but not aldosterone production, at all time points pi. Conclusions: These results, which provide insight into the host response following adenoviral infection of ACC cells, contribute to the understanding of the adrenal involvement during natural adenovirus infection and vector administration for gene therapy

First report outside Eastern Europe of West Nile virus lineage 2 related to the Volgograd 2007 strain, northeastern Italy, 2014

open11noWest Nile virus (WNV) is a Flavivirus transmitted to vertebrate hosts by mosquitoes, maintained in nature through an enzootic bird-mosquito cycle. In Europe the virus became of major public health and veterinary concern in the 1990s. In Italy, WNV re-emerged in 2008, ten years after the previous outbreak and is currently endemic in many areas of the country. In particular, the northeastern part of Italy experience continuous viral circulation, with human outbreaks caused by different genovariants of WNV lineage 1, Western-European and Mediterranean subcluster, and WNV lineage 2, Hungarian clade. Alongside the WNV National Surveillance Program that has been in place since 2002, regional surveillance plans were implemented after 2008 targeting mosquitoes, animals and humans.openRavagnan, Silvia; Montarsi, Fabrizio; Cazzin, Stefania; Porcellato, Elena; Russo, Francesca; Palei, Manlio; Monne, Isabella; Savini, Giovanni; Marangon, Stefano; Barzon, Luisa; Capelli, GioiaRavagnan, Silvia; Montarsi, Fabrizio; Cazzin, Stefania; Porcellato, Elena; Russo, Francesca; Palei, Manlio; Monne, Isabella; Savini, Giovanni; Marangon, Stefano; Barzon, Luisa; Capelli, Gioi