摘要： Bats are an important animal model with long lifespans, low incidences of tumorigenesis and an ability to asymptomatically harbour pathogens. Currently, in vivo studies of bats are hampered due to their low reproduction rates. To overcome this, we transplanted bat cells from bone marrow (BM) and spleen into an immunodeficient mouse strain NOD-scid IL-2R(-/-) (NSG), and have successfully established stable, long-term reconstitution of bat immune cells in mice (bat-mice). Immune functionality of our bat-mouse model was demonstrated through generation of antigen-specific antibody response by bat cells following immunization. Post-engraftment of total bat BM cells and splenocytes, bat immune cells survived, expanded and repopulated the mouse without any observable clinical abnormalities. Utilizing bat's remarkable immunological functions, this novel model has a potential to be transformed into a powerful platform for basic and translational research.

摘要： Spatiotemporally-localised prediction of virus emergence from wildlife requires focused studies on the ecology and immunology of reservoir hosts in their native habitat. Reliable predictions from mathematical models remain difficult in most systems due to a dearth of appropriate empirical data. Our goal was to study the circulation and immune dynamics of zoonotic viruses in bat populations and investigate the effects of maternally-derived and acquired immunity on viral persistence. Using rare age-specific serological data from wild-caught Eidolon helvum fruit bats as a case study, we estimated viral transmission parameters for a stochastic infection model. We estimated mean durations of around 6 months for maternally-derived immunity to Lagos bat virus and African henipavirus, whereas acquired immunity was long-lasting (Lagos bat virus: mean 12 years, henipavirus: mean 4 years). In the presence of a seasonal birth pulse, the effect of maternally-derived immunity on virus persistence within modelled bat populations was highly dependent on transmission characteristics. To explain previous reports of viral persistence within small natural and captive E. helvum populations, we hypothesise that some bats must experience prolonged infectious periods or within-host latency. By further elucidating plausible mechanisms of virus persistence in bat populations, we contribute to guidance of future field studies.

关键词： SARS冠状病毒   蝙蝠   抗病毒免疫   干扰素基因   埃博拉病毒   免疫反应   通道   体内  

摘要： 蝙蝠可以携带埃博拉病毒和SARS冠状病毒等多种病毒，但它们并不会因此而染病。近期，一项最新研究发现，蝙蝠体内一个被称为“干扰素基因刺激蛋白——干扰素”的抗病毒免疫通道受到抑制，使蝙蝠刚好能够抵御疾病，却不引发强烈的免疫反应。原因是蝙蝠体内一个抗病毒免疫通道受到抑制。

关键词： Bat viruses   Cambodia   Lao PDR   South East Asia   Environmental analysis   Evolution of environment   Emerging diseases  

摘要： Environmental modifications are leading to biodiversity changes, loss and habitat disturbance. This in turn increases contacts between wildlife and hence the risk of transmission and emergence of zoonotic diseases. We analyzed the environment and land use using remote spatial data around the sampling locations of bats positive for coronavirus (21 sites) and astrovirus (11 sites) collected in 43 sites. A clear association between viruses and hosts was observed. Viruses associated to synanthropic bat genera, such as Myotis or Scotophilus were associated to highly transformed habitats with human presence while viruses associated to fruit bat genera were correlated with natural environments with dense forest, grassland areas and regions of high elevation. In particular, group C betacoronavirus were associated with mosaic habitats found in anthropized environments.

关键词： Fruit bats   Bats   Neurons   Lyssavirus   Salivary glands   Motor neurons   Ganglia   Rabies virus  

摘要： Rabies is a fatal neurologic disease caused by lyssavirus infection. People are infected through contact with infected animals. The relative increase of human rabies acquired from bats calls for a better understanding of lyssavirus infections in their natural hosts. So far, there is no experimental model that mimics natural lyssavirus infection in the reservoir bat species. Lagos bat virus is a lyssavirus that is endemic in straw-colored fruit bats (Eidolon helvum) in Africa. Here we compared the susceptibility of these bats to three strains of Lagos bat virus (from Senegal, Nigeria, and Ghana) by intracranial inoculation. To allow comparison between strains, we ensured the same titer of virus was inoculated in the same location of the brain of each bat. All bats (n = 3 per strain) were infected, and developed neurological signs, and fatal meningoencephalitis with lyssavirus antigen expression in neurons. There were three main differences among the groups. First, time to death was substantially shorter in the Senegal and Ghana groups (4 to 6 days) than in the Nigeria group (8 days). Second, each virus strain produced a distinct clinical syndrome. Third, the spread of virus to peripheral tissues, tested by hemi-nested reverse transcriptase PCR, was frequent (3 of 3 bats) and widespread (8 to 10 tissues positive of 11 tissues examined) in the Ghana group, was frequent and less widespread in the Senegal group (3/3 bats, 3 to 6 tissues positive), and was rare and restricted in the Nigeria group (1/3 bats, 2 tissues positive). Centrifugal spread of virus from brain to tissue of excretion in the oral cavity is required to enable lyssavirus transmission. Therefore, the Senegal and Ghana strains seem most suitable for further pathogenesis, and for transmission, studies in the straw-colored fruit bat.

关键词： Vampire bats   Cattle   DNA viruses   Spillover   High-throughput sequencing   PCR  

摘要： Vampire bats are the only mammals known to feed exclusively on blood from other animals, often from domestic cattle. We tested the hypothesis that the adaptation of vampire bats to hematophagy would have resulted in shared viral communities among vampire bats and cattle, as a direct result of historic spillover events occurring due to hematophagy. We analyzed the presence of different viruses in sample populations of sympatric bat and prey populations and searched for shared viruses between taxa. A limited number of DNA viral groups were detected within each species. However, there was no evidence for a shared viral community among the vampire bat and cattle populations tested.

关键词： AKT signaling   RNA virus   bats   influenza   virulence factors  

摘要： Recently, two influenza A virus (FLUAV) genomes were identified in Central and South American bats. These sequences exhibit notable divergence from classical FLUAV counterparts, and functionally, bat FLUAV glycoproteins lack canonical receptor binding and destroying activity. Nevertheless, other features that distinguish these viruses from classical FLUAVs have yet to be explored. Here, we studied the viral nonstructural protein NS1, a virulence factor that modulates host signaling to promote efficient propagation. Like all FLUAV NS1 proteins, bat FLUAV NS1s bind double-stranded RNA and act as interferon antagonists. Unexpectedly, we found that bat FLUAV NS1s are unique in being unable to bind host p85 beta, a regulatory subunit of the cellular metabolism-regulating enzyme, phosphoinositide 3-kinase (PI3K). Furthermore, neither bat FLUAV NS1 alone nor infection with a chimeric bat FLUAV efficiently activates Akt, a PI3K effector. Structure-guided mutagenesis revealed that the bat FLUAV NS1-p85 beta interaction can be reengineered (in a strain-specific manner) by changing two to four NS1 residues (96L, 99M, 100I, and 145T), thereby creating a hydrophobic patch. Notably, ameliorated p85 beta -binding is insufficient for bat FLUAV NS1 to activate PI3K, and a chimeric bat FLUAV expressing NS1 with engineered hydrophobic patch mutations exhibits cell-type-dependent, but species-independent, propagation phenotypes. We hypothesize that bat FLUAV hijacking of PI3K in the natural bat host has been selected against, perhaps because genes in this metabolic pathway were differentially shaped by evolution to suit the unique energy use strategies of this flying mammal. These data expand our understanding of the enigmatic functional divergence between bat FLUAVs and classical mammalian and avian FLUAVs. IMPORTANCE The potential for novel influenza A viruses to establish infections in humans from animals is a source of continuous concern due to possible severe outbreaks or pandemic

关键词： DNA replication   DNA virus diseases   DNA viruses   PHYSIOLOGY   GENE amplification   GENETIC vectors   GENETIC aspects  

摘要： Circular replication-associated protein encoding single-stranded DNA (CRESS DNA) viruses are increasingly recognized worldwide in a variety of samples. Representative members include well-described veterinary pathogens with worldwide distribution, such as porcine circoviruses or beak and feather disease virus. In addition, numerous novel viruses belonging to the family Circoviridae with unverified pathogenic roles have been discovered in different human samples. Viruses of the family Genomoviridae have also been described as being highly abundant in different faecal and environmental samples, with case reports showing them to be suspected pathogens in human infections. In order to investigate the genetic diversity of these viruses in European bat populations, we tested guano samples from Georgia, Hungary, Romania, Serbia and Ukraine. This resulted in the detection of six novel members of the family Circoviridae and two novel members of the family Genomoviridae. Interestingly, a gemini-like virus, namely niminivirus, which was originally found in raw sewage samples in Nigeria, was also detected in our samples. We analyzed the nucleotide composition of members of the family Circoviridae to determine the possible host origins of these viruses. This study provides the first dataset on CRESS DNA viruses of European bats, and members of several novel viral species were discovered.

关键词： 中国科学家   SARS   疫情   蝙蝠   严重急性呼吸综合征   谜底   毒源   病毒感染  

摘要： 【英国《观察家报》网站12月10日报道】科学家找到了一个受病毒感染的蝙蝠种群,并把它与15年前神秘的严重急性呼吸综合征（SARS）疫情暴发联系起来。当年SARS在全球传播造成数百人死亡,但其源头始终未被查明。

关键词： bats   coronavirus   paramyxovirus   rats   Viet Nam   zoonotic viruses  

摘要： Bats and rodents are being increasingly recognized as reservoirs of emerging zoonotic viruses. Various studies have investigated bat viruses in tropical regions, but to date there are no data regarding viruses with zoonotic potential that circulate in bat and rat populations in Viet Nam. To address this paucity of data, we sampled three bat farms and three wet markets trading in rat meat in the Mekong Delta region of southern Viet Nam. Faecal and urine samples were screened for the presence of RNA from paramyxoviruses, coronaviruses and filoviruses. Paramyxovirus RNA was detected in 4 of 248 (1%) and 11 of 222 (4.9%) bat faecal and urine samples, respectively. Coronavirus RNA was detected in 55 of 248 (22%) of bat faecal samples;filovirus RNA was not detected in any of the bat samples. Further, coronavirus RNA was detected in 12 of 270 (4.4%) of rat faecal samples;all samples tested negative for paramyxovirus. Phylogenetic analysis revealed that the bat paramyxoviruses and bat and rat coronaviruses were related to viruses circulating in bat and rodent populations globally, but showed no cross-species mixing of viruses between bat and rat populations within Viet Nam. Our study shows that potentially novel variants of paramyxoviruses and coronaviruses commonly circulate in bat and rat populations in Viet Nam. Further characterization of the viruses and additional human and animal surveillance is required to evaluate the likelihood of viral spillover and to assess whether these viruses pose a risk to human health.