Since early November 2016, the number of laboratory-confirmed norovirus infections reported in Germany has been increasing steeply. Here, we report the detection and genetic characterisation of an emerging norovirus recombinant, GII.P16-GII.2. This strain was frequently identified as the cause of sporadic cases as well as outbreaks in nine federal states of Germany. Our findings suggest that the emergence of GII.P16-GII.2 contributed to rising case numbers of norovirus gastroenteritis in Germany.

Tumor necrosis factor (TNF)-alpha is a potent inducer of apoptotic cell death in various tissues, whereas the transcription factor nuclear factor (NF)-kappaB is essential to protect against TNF-alpha-induced apoptosis. Human hepatoma cell lines were used to investigate the effectiveness and specificity of the fungal metabolite gliotoxin in inhibiting TNF-alpha-induced NF-kappaB activation in transformed cells. Gliotoxin-TNF-alpha cotreatment induced massive apoptosis in these otherwise TNF-alpha-resistant cell lines. With the use of the mouse partial hepatectomy model, we were also able to demonstrate in vivo the capacity of gliotoxin to act as inhibitor of NF-kappaB activation. Bromodeoxyuridine staining of liver sections showed that the lack of NF-kappaB activation correlated with 80% reduction of DNA synthesis 48 h after hepatectomy compared with untreated controls. Additionally, animals treated with gliotoxin showed nuclear condensation and DNA laddering of hepatocytes indicative of apoptosis 24 h after hepatectomy. In summary, our results demonstrate that NF-kappaB is essential in defining the fate of liver cells in response to TNF-alpha in vivo and furthermore implicate gliotoxin as a potential new response modifier for TNF-alpha-based therapy.

The B-lymphotropic papovavirus (LPV) productively infects only a subset of human B-lymphoma-derived cell lines while transfection of the viral genome yields infectious viral particles in a much wider variety of human hematopoietic cell lines. We have analyzed the contribution of a putative LPV receptor on the cell surface of B-cell lines in restricting the virus host range. In order to establish a quantitative virus binding assay for LPV, infectious virus particles were highly purified by metrizamide equilibrium density centrifugation and used as immunogens to raise seven mouse monoclonal antibodies specific for LPV VP1. Virus particle binding was quantitated in an indirect, nonradioactive assay with an LPV VP1-specific enzyme-linked immunosorbent assay. Binding of LPV particles to permissive human B-lymphoma cell line BJA-B occured within minutes. Kinetics and capacity of binding were similar at 4 and 37°C. A BJA-B cell was estimated to bind approximately 600 virus particles at conditions under which 50% of the administered virus was bound. The sialidase and trypsin sensitivities of the cellular virus binding moiety show that sialylated and proteinaceous components are necessary components of the LPV receptor on BJA-B cells. Despite a high binding capacity of BJA-B cells for simian virus 40, LPV binding was not significantly affected by a 20-fold excess of simian virus 40 particles, indicating that these related polyomaviruses do not bind to the same receptor on BJA-B cells. Reduction of LPV binding to sialidase-pretreated BJA-B cells was accompanied by a similar reduction of infection, indicating that virus binding may be a limiting factor in the LPV replicative cycle. The two highly LPV-permissive human B-lymphoma cell lines BJA-B and Namalwa displayed high virus binding whereas low and nonpermissive hematopoietic cell lines showed reduced or undetectable virus binding. We conclude that the inability of LPV particles to productively infect the nonpermissive human hematopoietic cell lines analyzed is probably due to the absence or insufficient expression of a functional cell surface receptor.

AIM:To investigate molecular phenotypes of myocardial B19V-infection to determine the role of B19V in myocarditis and dilated cardiomyopathy (DCM). METHODS:Endomyocardial biopsies (EMBs) from 498 B19V-positive patients with myocarditis and DCM were analyzed using molecular methods and functional experiments. EMBs were obtained from the University Hospitals of Greifswald and Tuebingen and additionally from 36 German cardiology centers. Control tissues were obtained at autopsy from 34 victims of accidents, crime or suicide. Identification of mononuclear cell infiltrates in EMBs was performed using immunohistological staining. Anti-B19V-IgM and anti-B19V-IgG were analyzed by enzyme-linked immunosorbent assay (ELISA). B19V viral loads were determined using in-house quantitative real-time polymerase chain reaction (PCR). For B19V-genotyping a new B19V-genotype-specific restriction fragment length polymorphism (RFLP)-PCR was established. B19V-genotyping was verified by direct DNAsequencing and sequences were aligned using BLAST and BioEdit software. B19V P6-promoter and HHV6-U94-transactivator constructs were generated for cell culture experiments. Transfection experiments were conducted using human endothelial cells 1. Luciferase reporter assays were performed to determine B19V-replication activity. Statistical analysis and graphical representation were calculated using SPSS and Prism5 software. RESULTS:The prevalence of B19V was significantly more likely to be associated with inflammatory cardiomyopathy (iCMP) compared to uninflamed DCM (59.6% vs 35.3%) (P < 0.0001). The detection of B19V-mRNA replication intermediates proved that replication of B19V was present. RFLP-PCR assays showed that B19V-genotype 1 (57.4%) and B19V-genotype 2 (36.7%) were the most prevalent viral genotypes. B19V-genotype 2 was observed more frequently in EMBs with iCMP (65.0%) compared to DCM (35%) (P = 0.049). Although there was no significant difference in gender-specific B19V-loads, women were more frequently infected with B19V-genotype 2 (44.6%) than men (36.0%) (P = 0.0448 samples and was associated with higher B19V viral load compared to B19V-monoinfected tissue (P = 0.0012). The most frequent coinfecting virus was human herpes virus 6 (HHV6, 16.5%). B19V-coinfection with HHV6 showed higher B19V-loads compared to B19V-monoinfected EMBs (P = 0.0033), suggesting that HHV6 had transactivated B19V. In vitro experiments confirmed a 2.4-fold increased B19V P6-promoter activity by the HHV6 U94-transactivator. CONCLUSION:The finding of significantly increased B19V loads in patients with histologically proven cardiac inflammation suggests a crucial role of B19V-genotypes and reactivation of B19V-infection by HHV6-coinfection in B19V-associated iCMP. Our findings suggest that B19V-infection of the human heart can be a causative event for the development of an endothelial cell-mediated inflammatory disease and that this is related to both viral load and genotype.© 2014 Baishideng Publishing Group Co., Limited. All rights reserved.Key wor...