Protein Phosphatase 1 Regulates Human Cytomegalovirus Protein Translation by Restraining AMPK Signaling

Human cytomegalovirus (HCMV) carries the human protein phosphatase 1 (PP1) and other human proteins important for protein translation in its tegument layer for a rapid supply upon infection. However, the biological relevance behind PP1 incorporation and its role during infection is unclear. Additionally, PP1 is a difficult molecular target due to its promiscuity and similarities between the catalytic domain of multiple phosphatases. In this study, we circumvented these shortcomings by using 1E7-03, a small molecule protein–protein interaction inhibitor, as a molecular tool of noncatalytic PP1 inhibition. 1E7-03 treatment of human fibroblasts severely impaired HCMV replication and viral protein translation. More specifically, PP1 inhibition led to the deregulation of metabolic signaling pathways starting at very early time points post-infection. This effect was at least partly mediated by the prevention of AMP-activated protein kinase dephosphorylation, leading to elongation factor 2 hyperphosphorylation and reduced translation rates. These findings reveal an important mechanism of PP1 for lytic HCMV infection

Scientific Reports / Microbial Cryptotopes are Prominent Targets of B-cell Immunity

B-cell recognition of microbial antigens may be limited by masking of epitopes within three-dimensional structures (cryptotopes). Here we report that unmasking of cryptotopes by unfolding whole cytomegalovirus (CMV) antigen preparations with the chaotropic reagent Urea and probing with immune sera from healthy individuals (n=109) increased ELISA signals by 36% in comparison to folded CMV antigens (P<0.001). ELISA signals increased also significantly upon unfolding of S. aureus or E. coli antigens, whereas unfolded influenza H1N1 or respiratory syncitial virus antigens yielded reduced or unchanged reactivity in comparison to folded ones, respectively. Blocking of CMV cryptotope-specific Abs by incubation of an immunoglobuline preparation and three sera with unfolded CMV antigens enhanced clearly the neutralizing capacity of this immunoglobuline preparation against CMV infection. Thus, B-cell immunity frequently targets cryptotopes on CMV but these Abs are non-neutralizing, may reduce the neutralizing effectiveness of pathogen-specific Abs and increase during immune maturation following primary CMV infection. The observation of functional consequences of Abs specific for cryptotopes may open whole new avenues to a better understanding of the humoral immune response to CMV and development of more effective vaccines and immunoglobuline preparations.(VLID)468851

The Human Gastric Microbiome Is Predicated upon Infection with Helicobacter pylori

The human gastric lumen is one of the most hostile environments of the human body suspected to be sterile until the discovery of Helicobacter pylori (H.p.). State of the art next generation sequencing technologies multiply the knowledge on H.p. functional genomics as well as on the colonization of supposed sterile human environments like the gastric habitat. Here we studied in a prospective, multicenter, clinical trial the 16S rRNA gene amplicon based bacterial microbiome in a total of 30 homogenized and frozen gastric biopsy samples from eight geographic locations. The evaluation of the samples for H.p. infection status was done by histopathology and a specific PCR assay. CagA status was determined by a CagA-specific PCR assay. Patients were grouped accordingly as H.p.-negative, H.p.-positive but CagA-negative and H.p.-positive and CagA-positive (n = 10, respectively). Here we show that H.p. infection of the gastric habitat dominates the gastric microbiota in most patients and is associated with a significant decrease of the microbial alpha diversity from H.p. negative to H.p. positive with CagA as a considerable factor. The genera Actinomyces, Granulicatella, Veillonella, Fusobacterium, Neisseria, Helicobacter, Streptococcus, and Prevotella are significantly different between the H.p.-positive and H.p.-negative sample groups. Differences in microbiota found between CagA-positive and CagA-negative patients were not statistically significant and need to be re-evaluated in larger sample cohorts. In conclusion, H.p. infection dominates the gastric microbiome in a multicentre cohort of patients with varying diagnoses

Relative rate of evolution of the UL32 gene based on amino acid-sequence.

<p>The mean evolutionary rate per amino acid site within the UL32 gene was calculated to identify genomic regions with a more than average genomic variation. Relative evolutionary rates are shown for each site next to the site number. These rates are scaled such that the average evolutionary rate across all sites is 1 (dotted line). This means that sites showing a rate < 1 are evolving slower than average and those with a rate > 1 are evolving faster than average. These relative rates were estimated with the use of MEGA under the Jones-Taylor-Thornton model (+G) (21). Known immunogenic epitopes are indicated by horizontal bars above the graph [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0078925#B28" target="_blank">28</a>-<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0078925#B30" target="_blank">30</a>].</p

Kinetics of antibody levels in paired samples from CLL patients (n=64).

<p>The decay constant λ was calculated as mean change in log₁₀ titer per year. Positive values of λ indicate decay and negative values an increase in antibody levels over time. Statistical analysis was done using Spearman´s rho correlation coefficient which is shown for each comparison. (A) Decay per year of IgG subgroups plotted against total IgG decay. Lines indicate linear correlation and 95% confidence intervals, respectively. Decay of total IgG strongly correlated with that of IgG subgroups, p-values being <0.001 for all comparisons tested (not shown). (B) Decay constants of total IgG plotted against CMV-specific, VZV-specific, and EBV-specific IgG. Correlation between decay constants were statistically significant for total IgG and VZV- and EBV-specific IgG (p-values 0.003 and 0.001, respectively), while correlation between total IgG and CMV- specific IgG was not significant (p=0.087). (C) Decay constants of CMV-specific IgG plotted against CMV-subclass gB-specific and CMV-subclass pUL32-specific IgG. Correlations of decay constants were unspecific for both comparisons (p-values 0.068 and 0.405, respectively).</p

Phylogenetic analysis of the CMV UL32 gene.

<p>(A) Analysis of the N-terminal aa50-784 of the UL32 gene from CMV strains detected in our study (CLL, n=7; multiple myeloma, n=1; immunocompetent patients with primary CMV infections, n=5). (B) Analysis of the C-terminal aa493-1037 of the UL32 gene from the same CMV strains (CLL, n=7; multiple myeloma, n=1; immunocompetent patients with primary CMV infections, n=3). Sequences were compared to the published sequences of 3 laboratory adapted CMV strains and 11 previously described clinical isolates (see methods section) using the Jones-Taylor-Thornton model for constructing the tree with the maximum likelihood algorithm in MEGA. Robustness of the nodes was assessed with the Kimura two-parameter model for neighbor-joining algorithms and bootstrap-resampling. Bootstrap values (% after 1000 iterations) are shown for major branches. </p

Make EU trade with Brazil sustainable

Brazil, home to one of the planet's last great forests, is currently in trade negotiations with its second largest trading partner, the European Union (EU). We urge the EU to seize this critical opportunity to ensure that Brazil protects human rights and the environment