Cytomegaloviruses are known to encode several gene products that function to subvert MHC-dependent immune recognition. Here we characterize a rat cytomegalovirus (RCMV) C-type lectin-like (RCTL) gene product with homology to the Clr ligands for the NKR-P1 receptors. RCMV infection rapidly extinguished host Clr-b expression, thereby sensitizing infected cells to killing by natural killer (NK) cells. However, the RCTL protein functioned as a decoy ligand to protect infected cells from NK killing via direct interaction with the NKR-P1B inhibitory receptor. In vivo, an RCTL mutant virus displayed diminished virulence in an NK-dependent and strain-specific manner, suggesting that host NKR-P1 polymorphisms have evolved to avert the viral decoy mechanism while maintaining Clr-b recognition to preserve self tolerance. These findings reveal a unique strategy adopted by cytomegaloviruses to evade MHC-independent self-nonself discrimination. The existence of lectin-like genes in several poxviruses suggests that this may represent a common theme for viral evasion of innate immunity.

To investigate 2,017 cases of hantavirus disease in Germany, we compared 38 new patient-derived Puumala virus RNA sequences identified in 2010 with bank vole–derived small segment RNA sequences. The epidemic process was driven by outbreaks of 6 Puumala virus clades comprising strains of human and vole origin. Each clade corresponded to a different outbreak region.

We identified Dobrava-Belgrade virus infection in Turkey (from a strain related to hantavirus strains from nearby countries) in a patient who had severe symptoms leading to panhypopituitarism, but no known risk for hantavirus. Our findings emphasize the need for increased awareness of hantaviruses in the region and assessment of symptomatic persons without known risk factors for infection.

fThe complete genome of the English isolate of rat cytomegalovirus (RCMV-E) was determined. RCMV-E has a 202,946-bp genome with noninverting repeats but without terminal repeats. Thus, it differs significantly in size and genomic arrangement from closely related rodent cytomegaloviruses (CMVs). To account for the differences between the rat CMV isolates of Maastricht and England, RCMV-E was classified as Murid herpesvirus 8 by the International Committee on Taxonomy of Viruses. The English isolate of rat cytomegalovirus (RCMV-E) is a member of the Betaherpesvirinae subfamily of the Herpesviridae. Two isolates of RCMV, the Maastricht isolate (RCMV-M) and RCMV-E, have been reported, and RCMV-M has been classified as Murid herpesvirus 2 (MuHV-2). RCMV-M was first described in 1982 by Bruggeman et al. (2), and in the same year, Priscott and Tyrrell (4) reported on the existence of another rat CMV that was later termed the "English" isolate (3). Both viruses had been isolated from Rattus norvegicus.The complete genome sequences of both MuHV-2 and MuHV-1 (MCMV Smith strain) have been published (NC_002512, 230,138 bp [ 7] and NC_004065, 230,278 bp [5]) as well as those of four very closely related isolates of MuHV-1 (6). The RCMV-M and RCMV-E genomes were shown to have significantly different restriction enzyme cleavage patterns, suggesting that they represent different betaherpesvirus species rather than different strains of the same virus (1,8).To analyze the viral genome, RCMV-E virion DNA was isolated from RCMV-E-infected rat embryo fibroblasts and analyzed by Sanger sequencing. In addition, shotgun sequencing (Macrogen, South Korea) with low coverage was performed. These data revealed substantial differences to MuHV-2 and served as a scaffold sequence. To confirm the data, RCMV-E virion DNA was subjected to 454 sequencing. The DNA was sheared with Covaris S2, and libraries were generated utilizing the rapid library kit and finally sequenced with Titanium chemistry on a 454 FLX instrument (Roche). Reads with a 26-fold coverage were mapped to our scaffold sequence data using Newbler 2.6 software. Analysis of the data showed that the RCMV-E genome comprises 202,946 bp. Results of a de novo assembly using Newbler 2.6 confirmed the results of the mapping. Therefore, from both physical analysis and the genome sequencing data, it is evident that the RCMV-E genome is considerably smaller than and thus differs significantly in size and gene content from both MuHV-1 and MuHV-2.Major criteria to identify open reading frames (ORFs) were a minimum length of 60 bp, an ATG start codon, and less than 60% overlap with adjacent ORFs. By this approach, 140 ORFs were identified using Lasergene 8 and Geneious 5.4 software packages. A total of 118 ORFs are homologous to MuHV-1 and MuHV-2, showing an E value of Ͻ0.001 in BLASTX analyses. Both at the nucleotide and protein levels, most RCMV genes are somewhat more closely related to MuHV-1, although they are almost equally divergent from both MuHV-1 and MuHV-2. However, RCMV-E encodes ...

Members of the Dobrava-Belgrade virus (DOBV) species are hantaviruses carried by different Apodemus mice as reservoir hosts and causing haemorrhagic fever with renal syndrome (HFRS) in humans. In Central Europe, the Kurkino genotype of DOBV, associated with the striped field mouse, Apodemus agrarius, is prevalent. This paper presents the first extensive study of the serological and molecular diagnostics, epidemiology and clinics of DOBV-Kurkino infections in Central Europe. Serum samples from 570 German patients living in the habitat of A. agrarius (north and northeast Germany) and exhibiting febrile disease, were analysed. All samples were tested by ELISA, subsets of samples were also analysed by immunoblot, neutralization assay, and RT-PCR. A group of 86 individuals was confirmed as DOBV-infected. The virus neutralization assay allowed a reliable identification of DOBV antibodies during both acute and convalescent phases of infection. However, differentiation of relevant DOBV genotypes was not possible by neutralization test but required molecular analysis. Whereas DOBV IgM antibodies tend to persist in the infected organism, RNAaemia seems to be short. Nucleotide sequences were amplified from four patients, and their analysis demonstrated infection by DOBV-Kurkino. With respect to the initial results, the high degree of identity of local patient-derived and A. agrarius-derived virus sequences may allow a closer allocation of the geographical place where the human infection occurred. In contrast to moderate/severe HFRS caused by the DOBV genotypes Dobrava or Sochi, all available data showed a mild clinical course of HFRS caused by DOBV-Kurkino infection without lethal outcomes.