Puumala virus (PUUV) is the most important hantavirus species in Central Europe. Nephropathia epidemica (NE), caused by PUUV, is characterized by acute renal injury (AKI) with thrombocytopenia and frequently gastrointestinal symptoms.
Methods
456 patients with serologically and clinically confirmed NE were investigated at time of follow-up in a single clinic. The course of the NE was investigated using medical reports. We identified patients who had endoscopy with intestinal biopsy during acute phase of NE. Histopathological, immunohistochemical and molecular analyses of the biopsies were performed.
Results
Thirteen patients underwent colonoscopy or gastroscopy for abdominal pain, diarrhea, nausea and vomiting during acute phase of NE. Immunohistochemistry (IHC) revealed PUUV nucleocapsid antigen in 11 biopsies from 8 patients; 14 biopsies from 5 patients were negative for PUUV nucleocapsid antigen. IHC localized PUUV nucleocapsid antigen in endothelial cells of capillaries or larger vessels in the lamina propria. Rate of AKI was not higher and severity of AKI was not different in the PUUV-positive compared to the PUUV-negative group. All IHC positive biopsies were positive for PUUV RNA using RT-PCR. Phylogenetic reconstruction revealed clustering of all PUUV strains from this study with viruses previously detected from the South-West of Germany. Long-term outcome was favorable in both groups.
Conclusions
In patients with NE, PUUV nucleocapsid antigen and PUUV RNA was detected frequently in the intestine. This finding could explain frequent GI-symptoms in NE patients, thus demonstration of a more generalized PUUV infection. The RT-PCR was an effective and sensitive method to detect PUUV RNA in FFPE tissues. Therefore, it can be used as a diagnostic and phylogenetic approach also for archival materials. AKI was not more often present in patients with PUUV-positive IHC. This last finding should be investigated in larger numbers of patients with PUUV infection. 相似文献
Hantavirus infection is a global health challenge, causing widespread public concern. In recent years, cases of hantavirus infection in pregnant women have been reported in many countries. The infected pregnant women and their fetuses appear to have more severe clinical symptoms and worse clinical outcomes. Hence, to study the prevalence of hantavirus infection in pregnant women, this study will focus on the epidemiological distribution of the virus, different virus species penetrating the placental barrier, and factors affecting the incidence and clinical outcome of the infection in pregnant women and their fetuses. In addition, this review will also discuss the diagnostic tools and treatments for pregnant patients and provide an overview of the relevant future research. 相似文献
Hantaviruses are enveloped, negative-strand RNA viruses which can be lethal to humans, causing either a hemorrhagic fever with renal syndrome or a hantaviral pulmonary syndrome. The viral genomes consist of three RNA segments: the L segment encodes the viral polymerase, the M segment encodes the viral surface glycoproteins G1 and G2, and the S segment encodes the nucleocapsid (N) protein. The N protein is a 420- to 430-residue, 50-kDa protein which appears to direct hantavirus assembly, although mechanisms of N protein oligomerization, RNA encapsidation, budding, and release are poorly understood. We have undertaken a biochemical and genetic analysis of N protein oligomerization. Bacterially expressed N proteins were found by gradient fractionation to associate not only as large multimers or aggregates but also as dimers or trimers. Chemical cross-linking of hantavirus particles yielded N protein cross-link products with molecular masses of 140 to 150 kDa, consistent with the size of an N trimer. We also employed a genetic, yeast two-hybrid method for monitoring N protein interactions. Analyses showed that the C-terminal half of the N protein plus the N-terminal 40 residues permitted association with a full-length N protein fusion. These N-terminal 40 residues of seven different hantavirus strains were predicted to form trimeric coiled coils. Our results suggest that coiled-coil motifs contribute to N protein trimerization and that nucleocapsid protein trimers are hantavirus particle assembly intermediates. 相似文献
Puumala virus (PUUV) is a negative-stranded RNA virus in the genus Hantavirus, family Bunyaviridae. In this study, detailed phylogenetic analysis was performed on 42 complete S segment sequences of PUUV originated from several European countries, Russia, and Japan, the largest set available thus far for hantaviruses. The results show that PUUV sequences form seven distinct and well-supported genetic lineages; within these lineages, geographical clustering of genetic variants is observed. The overall phylogeny of PUUV is star-like, suggesting an early split of genetic lineages. The individual PUUV lineages appear to be independent, with the only exception to this being the Finnish and the Russian lineages that are closely connected to each other. Two strains of PUUV-like virus from Japan form the most ancestral lineage diverging from PUUV. Recombination points within the S segment were searched for and evidence for intralineage recombination events was seen in the Finnish, Russian, Danish, and Belgian lineages of PUUV. Molecular clock analysis showed that PUUV is a stable virus, evolving slowly at a rate of 0.7 x 10(-7) to 2.2 x 10(-6) nt substitutions per site per year. 相似文献
Dendritic cells (DCs) play a pivotal role as antigen-presenting cells in the antiviral immune response. Here we show that Hantaan virus (HTNV), which belongs to the Bunyaviridae family (genus Hantavirus) and causes hemorrhagic fever with renal syndrome, productively infects human DCs in vitro. In the course of HTNV infection, DCs did not show any cytopathic effect and viral replication did not induce cell lysis or apoptosis. Furthermore, HTNV did not affect apoptosis-inducing signals that are important for the homeostatic control of mature DCs. In contrast to immunosuppressive viruses, e.g., human cytomegalovirus, HTNV activated immature DCs, resulting in upregulation of major histocompatibility complex (MHC), costimulatory, and adhesion molecules. Intriguingly, strong upregulation of MHC class I molecules and an increased intercellular cell adhesion molecule type 1 expression was also detected on HTNV-infected endothelial cells. In addition, antigen uptake by HTNV-infected DCs was reduced, another characteristic feature of DC maturation. Consistent with these findings, we observed that HTNV-infected DCs stimulated T cells as efficiently as did mature DCs. Finally, infection of DCs with HTNV induced the release of the proinflammatory cytokines tumor necrosis factor alpha and alpha interferon. Taken together, our findings indicate that hantavirus-infected DCs may significantly contribute to hantavirus-associated pathogenesis. 相似文献
In this report the basis for the structural architecture of the envelope of hantaviruses, family Bunyaviridae, is systematically studied by the interactions of two glycoproteins N and C (Gn and Gc, respectively) and their respective disulfide bridge-mediated homo- and heteromeric oligomerizations. In virion extracts Gn and Gc associated in both homo- and hetero-oligomers which were, at least partially, thiol bridge mediated. Due to strong homo-oligomerization, the hetero-oligomers of Gn and Gc are likely to be mediated by homo-oligomeric subunits. A reversible pH-induced disappearance of a neutralizing epitope in Gc and dissociation of the Gn-Gc complex at pH values below 6.2 provide proteochemical evidence for the fusogenicity of Gc. Incomplete inactivation of virions at acidic pH indicates that additional factors are required for hantavirus fusion, as in the case of pestiviruses of the Flaviviridae. Based on similarities to class II fusion proteins, a structure model was created of hantavirus Gc using the Semliki Forest virus E1 protein as a template. In total, 10 binding regions for Gn were found by peptide scanning, of which five represent homotypic (GnI to GnV) and five represent heterotypic (GcI to GcV) interaction sites that we assign as intra- and interspike connections, respectively. In conclusion, the glycoprotein associations were compiled to a model wherein the surface of hantaviruses is formed of homotetrameric Gn complexes interconnected with Gc homodimers. This organization would create the grid-like surface pattern described earlier for hantaviruses in negatively stained electron microscopy specimens.Hantaviruses, a genus in the family Bunyaviridae, are rodent- and insectivore-borne zoonotic viruses that are seemingly apathogenic to the carrier rodents (39, 57). A number of hantaviruses are human pathogens that in areas of endemicity are responsible for two diseases: hemorrhagic fever with renal syndrome in Eurasia and hantavirus cardiopulmonary syndrome in the Americas (49, 57, 61). Hantaviruses are enveloped viruses and have a trisegmented, single-stranded, negative-sense RNA genome that encodes an RNA-dependent RNA polymerase, two glycoproteins, and a nucleocapsid protein (22, 34, 49, 60). During assembly, the four proteins and the RNA genome are packed into a round or a pleomorphic particle enveloped with a lipid bilayer. The interactions among the structural components of hantavirus have not been described in sufficient detail to construct the basic architecture of the virus particle or to understand the mechanisms of its assembly and entry.The envelope glycoproteins are expressed as a precursor polypeptide, which is cotranslationally cleaved after a conserved pentapeptide WAASA into an N- and C-terminal portion prior to maturation of the envelope glycoproteins proteins N and C (Gn and Gc, respectively) (27). In the family Bunyaviridae the transport of newly synthesized glycoproteins from endoplasmic reticulum to the Golgi apparatus requires the presence of both Gn and Gc (36, 37, 50, 53). Recombinant coexpression of the hantavirus glycoproteins is sufficient to achieve proper folding and the expected cellular localization at the Golgi even when the glycoproteins are not expressed from a common precursor (6, 36, 50). This suggests that the expression of the precursor is not a prerequisite for interactions between Gn and Gc during maturation in which the formation of a Gn-Gc complex results in exposure of a conformational Golgi apparatus-targeting signal, present only in the heterodimeric Gn-Gc complex (6, 50).Entry of enveloped viruses via recognition of the cell surface receptors and subsequent fusion of the virus and cell membranes are accomplished by viral glycoproteins which often appear in homo- and/or heteromeric complexes. For example, the E1 and E2 of Semliki Forest virus (SFV) form a trimer of heterodimers (45), and the E protein of tick-borne encephalitis virus (TBEV) forms a homodimer (41) while the hemagglutinin of influenza A virus (67) and the S protein of severe acute respiratory syndrome coronavirus associate in homotrimers (4, 5). The mature glycoproteins extracted from virions of Uukuniemi phlebovirus exist as homodimers (44), whereas glycoprotein complex formations of many other members of the Bunyaviridae have not been defined. The viral fusion proteins can be classified into class I, class II, and class III (25). Between classes I and II, a distinguishing property is the orientation of a fusion protein in the metastable state. The class I proteins are oriented perpendicular to the viral membrane, and the class II protein is parallel to the viral membrane (7). The class II viral fusion proteins assemble in virions as metastable homo- or heterodimeric complexes which, upon exposure to low pH, fuse the viral and target cellular membranes (7). This process begins with a conformational change in the fusion protein, leading to the revelation of its fusion loop, which binds to the cellular target membrane (7). Additionally, the formation of a homotrimeric fusion protein complex and structural changes that drive the fusion into completion occur (7).Understanding the multimeric status, protein-protein interactions, and pH-dependent conformational changes of glycoproteins is paramount to our understanding of selectivity in cell receptor binding and mechanisms of virus entry. It is unknown whether higher-order oligomeric complexes are found in hantavirus particles. Many neutralizing monoclonal antibodies (MAbs) have been isolated and by MAb escape mutants shown to recognize epitopes in both Gn and Gc, typically localized at discontinuous sites (15). Different neutralization mechanisms for hantavirus MAbs have been elucidated. These range from inhibiting receptor binding to inhibition of virus fusion (2, 23, 28, 30, 65). It is known that hantaviral glycoproteins possess fusogenic activity. Glycoproteins of hantaviruses that cause hemorrhagic fever with renal syndrome can induce syncytia when subjected to low pH (32, 35), and infection by Hantaan virus was shown to use low-pH-dependent clathrin-mediated endocytosis (19). Hantavirus Gc is suggested to be a class II fusion protein (13, 55), and the N-linked glycosylation of Gc is essential for cell fusion activity (70); but no clear understanding exists of the fusion mechanism or conformational changes that mediate uncoating of virions after entry.Our study supports the hypothesis that the Gc of hantaviruses is a class II fusion protein. We show the interaction between Gn and Gc to be pH sensitive and dissociation to start at a pH below 6.4. The low-pH-induced Gc dissociation from Gn was reversible, suggesting that the conformational changes in Gc are also reversible. Both glycoproteins were found to form homodimeric and hetero-oligomeric complexes in virion extracts through thiol bridging. Interaction studies further suggested that the protruding part of the spike complex in the hantavirus virion consists of four Gn subunits and that the spike complexes interconnect with homodimeric Gc subunits. Finally, we mapped and compiled the interaction sites of Gn and Gc proteins in a class II fusion protein three-dimensional (3D) model of Gc. The identified Gn-Gn, Gn-Gc, and Gc-Gc interaction sites may play an important role in glycoprotein folding and maturation, spike assembly, virus fusion, and neutralization of infection. 相似文献
Hantaviruses are rodent-borne bunyaviruses which cause haemorrhagic fever with renal syndrome and Hantavirus pulmonary syndrome in humans. This review covers the host interactions of the viruses, including the rodent reservoirs, the clinical outcome of human infections as well as the pathogenesis and laboratory diagnosis of infections. The current stage in prophylaxis and therapy of hantaviral diseases is described and different approaches in vaccine development are discussed. 相似文献
Hantaviruses are enveloped RNA viruses that persistently infect rodent hosts without ill-effect. The host persistently excretes virus in urine and saliva. Man becomes infected from the rodents when one enters the ecological niche of the other. There are two major clinical presentations--haemorrhagic fever with renal syndrome, found worldwide in various forms and hantavirus pulmonary syndrome, found only in the Americas. This review examines the virology, epidemiology and pathogenesis of these emerging pathogens. 相似文献
A novel hantavirus, first detected in Siberian lemmings (Lemmus sibiricus) collected near the Topografov River in the Taymyr Peninsula, Siberia (A. Plyusnin et al., Lancet 347:1835-1836, 1996), was isolated in Vero E6 cells and in laboratory-bred Norwegian lemmings (Lemmus lemmus). The virus, named Topografov virus (TOP), was most closely related to Khabarovsk virus (KBR) and Puumala viruses (PUU). In a cross focus reduction neutralization test, anti-TOP Lemmus antisera showed titers at least fourfold higher with TOP than with other hantaviruses; however, a rabbit anti-KBR antiserum neutralized TOP and KBR at the same titer. The TOP M segment showed 77% nucleotide and 88% amino acid identity with KBR and 76% nucleotide and 82% amino acid identity with PUU. However, the homology between TOP and the KBR S segment was disproportionately higher: 88% at the nucleotide level and 96% at the amino acid level. The 3' noncoding regions of KBR and the TOP S and M segments were alignable except for 113- and 58-nucleotide deletions in KBR. The phylogenetic relationships of TOP, KBR, and PUU and their respective rodent carriers suggest that an exceptional host switch took place during the evolution of these viruses; while TOP and KBR are monophyletic, the respective rodent host species are only distantly related. 相似文献
Hantaviruses are comprised of tri-segmented negative sense single-stranded RNA, and are members of the Bunyaviridae family. Hantaviruses are distributed worldwide and are important zoonotic pathogens that can have severe adverse effects in humans. They are naturally maintained in specific reservoir hosts without inducing symptomatic infection. In humans, however, hantaviruses often cause two acute febrile diseases, hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS). In this paper, we review the epidemiology and epizootiology of hantavirus infections worldwide.
We developed a compartmental model for hantavirus infection in deer mice (Peromyscus maniculatus) with the goal of comparing relative importance of direct and indirect transmission in sylvan and peridomestic environments.
A direct transmission occurs when the infection is mediated by the contact of an infected and an uninfected mouse, while an
indirect transmission occurs when the infection is mediated by the contact of an uninfected mouse with, for instance, infected
soil. Based on population dynamics data and estimates of hantavirus decay in the two types of environments, our model predicts
that direct transmission dominates in the sylvan environment, while both pathways are important in peridomestic environments.
The model allows us to compute a basic reproduction number R0, which indicates whether the virus will be endemic or eradicated from the mouse population, in both an autonomous and a time-periodic
model. Our analysis can be used to evaluate various eradication strategies. 相似文献
Oecologia - Species diversity has been proposed to decrease prevalence of disease in a wide variety of host–pathogen systems, in a phenomenon labeled the dilution effect. This phenomenon was... 相似文献