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Berlin, Germany

Eifler M.,Charite - Medical University of Berlin | Eifler M.,TIB MOLBIOL GmbH | Uecker R.,Charite - Medical University of Berlin | Weisbach H.,Charite - Medical University of Berlin | And 11 more authors.
PLoS Pathogens | Year: 2014

Entry into mitosis is accompanied by dramatic changes in cellular architecture, metabolism and gene expression. Many viruses have evolved cell cycle arrest strategies to prevent mitotic entry, presumably to ensure sustained, uninterrupted viral replication. Here we show for human cytomegalovirus (HCMV) what happens if the viral cell cycle arrest mechanism is disabled and cells engaged in viral replication enter into unscheduled mitosis. We made use of an HCMV mutant that, due to a defective Cyclin A2 binding motif in its UL21a gene product (pUL21a), has lost its ability to down-regulate Cyclin A2 and, therefore, to arrest cells at the G1/S transition. Cyclin A2 up-regulation in infected cells not only triggered the onset of cellular DNA synthesis, but also promoted the accumulation and nuclear translocation of Cyclin B1-CDK1, premature chromatin condensation and mitotic entry. The infected cells were able to enter metaphase as shown by nuclear lamina disassembly and, often irregular, metaphase spindle formation. However, anaphase onset was blocked by the still intact anaphase promoting complex/cyclosome (APC/C) inhibitory function of pUL21a. Remarkably, the essential viral IE2, but not the related chromosome-associated IE1 protein, disappeared upon mitotic entry, suggesting an inherent instability of IE2 under mitotic conditions. Viral DNA synthesis was impaired in mitosis, as demonstrated by the abnormal morphology and strongly reduced BrdU incorporation rates of viral replication compartments. The prolonged metaphase arrest in infected cells coincided with precocious sister chromatid separation and progressive fragmentation of the chromosomal material. We conclude that the Cyclin A2-binding function of pUL21a contributes to the maintenance of a cell cycle state conducive for the completion of the HCMV replication cycle. Unscheduled mitotic entry during the course of the HCMV replication has fatal consequences, leading to abortive infection and cell death. © 2014 Eifler et al. Source

Liao R.S.,PeaceHealth Laboratories | Landt O.,TIB MOLBIOL GmbH | Hill J.T.,PeaceHealth Laboratories
Diagnostic Microbiology and Infectious Disease | Year: 2011

We evaluated the performance of a laboratory-developed multiplex real-time reverse transcription-PCR assay (LDT rRT-PCR), the Centers for Disease Control and Prevention (CDC) 2009 H1N1 rRT-PCR protocol using the LightCycler 480 II, the multiplex xTAG Respiratory Virus Panel (xTAG RVP), and rapid immunodiagnostic testing (RIDT) using the BinaxNOW Influenza A & B to detect 2009 H1N1 with 426 nasopharyngeal swab specimens during the 2009 H1N1 pandemic. The specificity of the methods tested was ≥98%, and the individual test sensitivities were RIDT at 42.3% [95% confidence interval (CI), 31.4-54.0], LDT rRT-PCR at 98.9% (95% CI, 92.9-99.9), CDC 2009 H1N1 rRT-PCR at 78.2% (95% CI, 67.8-86.0), and xTAG RVP at 93.1% (95% CI, 85.0-97.2). A negative RIDT result should not be used to make decisions with respect to treatment or infection prevention. rRT-PCR is the preferred first-line diagnostic test for detecting 2009 H1N1 influenza A. © 2011 Elsevier Inc. Source

Rihs H.-P.,Ruhr University Bochum | Lotz A.,Ruhr University Bochum | Rueff F.,Ludwig Maximilians University of Munich | Landt O.,TIB MOLBIOL GmbH | And 2 more authors.
Journal of Toxicology and Environmental Health - Part A: Current Issues | Year: 2012

It is a matter of debate whether single nucleotide polymorphisms (SNP) in the promoter region of interleukin (IL)-13, an IgE regulator, and IL-18, an inducer of immune responses, modulating the respective protein expression, are accompanied by an increased risk of atopy, allergic asthma, and total IgE levels. The suspected associations were noted in health care workers (HCW) with and without latex allergy. IL-13 (-1055C>T) and three IL-18 (-656T>G, -607C>A, -137G>C) SNP were studied in 523 HCW with natural rubber latex (NRL) exposure and diagnosis in the late 1990s. Three hundred and thirty-four HCW displayed NRL sensitization and allergic symptoms, 93 with latex-allergic asthma, and 189 HCW with neither symptoms nor NRL sensitization. SNP analyses were performed by real-time polymerase chain reaction (PCR) using newly developed LightCycler assays. Analysis of IL-13 -1055C>T by analysis of variance (ANOVA) revealed significantly elevated total IgE levels in HCW carrying the CT or TT variant compared with the CC variant. None of the studied SNP showed an association with NRL-specific IgE. The IL-18 variants -656GG and -607CC displayed 99.5% linkage disequilibrium. Frequencies of alleles -656GG and -607CC were elevated in HCW with NRL asthma (48.4%) compared with HCW without symptoms (37.6%). In contrast, IL-18 -137G>C variants displayed an overall homogenous distribution. The association between the IL-13 -1055T allele and elevated total IgE levels confirms the role of a genetic background for total IgE regulation. The studied IL-18 SNP demonstrated no significant association with the clinical outcome, total IgE, or specific IgE in HCW with natural rubber latex allergy. Copyright © Taylor & Francis Group, LLC. Source

Steiner B.,University of Zurich | Rosendahl J.,University of Leipzig | Witt H.,Charite - Medical University of Berlin | Teich N.,Internistische Gemeinschaftspraxis fur Verdauungs und Stoffwechselerkrankungen | And 21 more authors.
Human Mutation | Year: 2011

CFTR mutations enhance susceptibility for idiopathic chronic pancreatitis (ICP) and congenital bilateral absence of the vas deferens (CBAVD); however, it is unknown why CFTR heterozygotes are at increased disease risk. We recently showed that common CFTR variants are associated with aberrantly spliced transcripts. Here, we genotyped for common CFTR variants and tested for associations in two ICP (ICP-A: 126 patients, 319 controls; ICP-B: 666 patients, 1,181 controls) and a CBAVD population (305 patients, 319 controls). Haplotype H10 (TG11-T7-470V) conferred protection (ICP-A: OR 0.19, P<0.0001; ICP-B: OR 0.78, P = 0.06; CBAVD OR 0.08, P<0.001), whereas haplotype H3 (TG10-T7-470M) increased disease risk (ICP-A: OR 8.34, P = 0.003; ICP-B: OR 1.88, P = 0.007; CBAVD: OR 5.67, P = 0.01). The risk of heterozygous CFTR mutations carriers for ICP (OR 2.44, P<0.001) and CBAVD (OR 14.73, P<0.001) was fully abrogated by the H10/H10 genotype. Similarly, ICP risk of heterozygous p.Asn34Ser SPINK1 mutation carriers (OR 10.34, P<0.001) was compensated by H10/H10. Thus, common CFTR haplotypes modulate ICP and CBAVD susceptibility alone and in heterozygous CFTR and p.Asn34Ser mutation carriers. Determination of these haplotypes helps to stratify carriers into high- and low-risk subjects, providing helpful information for genetic counseling. © 2011 Wiley-Liss, Inc. Source

Frangoulidis D.,University of Federal Defense Munich | Splettstoesser W.D.,University of Federal Defense Munich | Landt O.,TIB MOLBIOL GmbH | Dehnhardt J.,TIB MOLBIOL GmbH | And 7 more authors.
PLoS ONE | Year: 2013

The acute disease antigen A (adaA) gene is believed to be associated with Coxiella burnetii strains causing acute Q fever. The detailed analysis of the adaA genomic region of 23 human- and 86 animal-derived C. burnetii isolates presented in this study reveals a much more polymorphic appearance and distribution of the adaA gene, resulting in a classification of C. burnetii strains of better differentiation than previously anticipated. Three different genomic variants of the adaA gene were identified which could be detected in isolates from acute and chronic patients, rendering the association of adaA positive strains with acute Q fever disease disputable. In addition, all adaA positive strains in humans and animals showed the occurrence of the QpH1 plasmid. All adaA positive isolates of acute human patients except one showed a distinct SNP variation at position 431, also predominant in sheep strains, which correlates well with the observation that sheep are a major source of human infection. Furthermore, the phylogenetic analysis of the adaA gene revealed three deletion events and supported the hypothesis that strain Dugway 5J108-111 might be the ancestor of all known C. burnetii strains. Based on our findings, we could confirm the QpDV group and we were able to define a new genotypic cluster. The adaA gene polymorphisms shown here improve molecular typing of Q fever, and give new insights into microevolutionary adaption processes in C. burnetii. © 2013 Frangoulidis et al. Source

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