关键词： 蝙蝠   人畜共患病毒   免疫系统   病毒  

摘要： 蝙蝠是多种人畜共患病毒的主要宿主,其对病毒的耐受/应答机制受到越来越多关注。本文就蝙蝠携带病毒概况,蝙蝠特殊生理组成与携带病毒的关系,蝙蝠的固有免疫和适应性免疫系统对病毒耐受/应答的可能机制等进行综述,鉴于目前对蝙蝠的生物学系统研究较少,对蝙蝠免疫系统进一步研究方向进行展望。

关键词： 老挝北部   蝙蝠   关键特征   病毒   《自然》  

摘要： 日前,与《自然》合作的预印本服务器Research Square上发布了一篇有关冠状病毒的研究论文。法国巴斯德研究所和老挝大学的研究人员合作,发现由老挝北部洞穴蝙蝠传播的几种病毒与新冠病毒(SARS-CoV-2)高度相似,尤其是在与感染人类细胞有关的关键特征上,是目前已知的与新冠病毒最为接近的病毒。

关键词： Codon usage bias   Horseshoe bat hepatitis B virus   Rhinolophus sinicus   Mutation pressure   Natural selection  

摘要： In the present analysis, codon usage strategies and base distribution of Horseshoe bat hepatitis B virus (HBHBV) were analyzed and compared with its host Rhinolophus sinicus, as no work was yet reported. The magnitude of synonymous codon usage bias (CUB) in the virus and its host was low with higher proportion of the base C. Notably, 21 more frequently used codons, 19 less frequently used codons and 3 underrepresented codons (TCG, ACG and GCG) were found to be similar in both virus and its host coding sequences. Neutrality plot analysis reported greater role of natural selection in HBHBV (67.84%) and R. sinicus (76.90%) over mutation pressure. Base skewness and protein properties also influenced the CUB of genes. Further, codon usage analysis depicted, HBHBV and R. sinicus had many similarities in codon usage patterns that might reflect viral adaptation to its host.

关键词： SARS-CoV-2   COVID-19   coronavirus   evolution   bats   phylogeny   spike protein   swine acute diarrhea syndrome   porcine epidemic diarrhea virus  

摘要： Despite the discovery of animal coronaviruses related to SARS-CoV-2, the evolutionary origins of this virus are elusive. We describe a meta-transcriptomic study of 411 bat samples collected from a small geographical region in Yunnan province, China, between May 2019 and November 2020. We identified 24 full-length coronavirus genomes, including four novel SARS-CoV-2-related and three SARS-CoV-related viruses. Rhinolophus pusillus virus RpYN06 was the closest relative of SARS-CoV-2 in most of the genome, although it possessed a more divergent spike gene. The other three SARS-CoV-2-related coronaviruses carried a genetically distinct spike gene that could weakly bind to the hACE2 receptor in vitro. Ecological modeling predicted the co-existence of up to 23 Rhinolophus bat species, with the largest contiguous hot-spots extending from South Laos and Vietnam to southern China. Our study highlights the remarkable diversity of bat coronaviruses at the local scale, including close relatives of both SARS-CoV-2 and SARS-CoV.

关键词： Chimeric bat influenza viruses   Replication and virulence   Mammalian and avian cells   Mice  

摘要： Previous studies have shown that chimeric bat influenza viruses can be generated by reverse genetic system. However, the roles of the surface or internal genes of chimeric bat influenza viruses in viral replication and virulence in different host species were still not completely understood. In this study, we generated a chimeric H9N2 bat virus with both HA and NA surface genes from the avian A2093/H9N2 virus and compared its replication and virulence with the chimeric H1N1 bat virus with both HA and NA from the PR8/H1N1 virus in vitro and in mice. The chimeric H1N1 virus showed significantly higher replication in mammalian and avian cells and significantly higher virulence in mice than the chimeric H9N2 virus. Moreover, the chimeric H9N2 virus with the bat influenza internal M gene showed a higher replication in mammalian cells than in avian cells. While the chimeric H9N2 virus with the avian-origin viral M gene displayed a higher replication than that with the bat influenza M gene in avian cells, which likely resulted from increased receptor binding ability to alpha 2,3 sialic acid linked glycans of the former virus. Our study indicates that bat influenza internal genes are permissive in both mammalian and avian cells, and the bat influenza internal M gene shows more compatibility in mammals than in the avian host. Although the surface genes play more critical roles for viral replication in different host substrates, influenza M gene also potentially impacts on replication, virulence and host tropism.

关键词： 皂甙   多糖   腺苷   免疫功能   小鼠  

摘要： 目的测定石斛人参蝙蝠蛾姜胶囊中功效成分人参皂甙、多糖和腺苷的含量,研究石斛人参蝙蝠蛾姜胶囊对CI/F1(BALB/c×ICR)雌性小鼠的免疫调节作用。方法采用比色法测定人参皂甙和多糖,采用液相色谱法(HPLC)测定腺苷;采用小鼠经口灌胃分别给予260、530、1580 mg/kg的石斛人参蝙蝠蛾姜胶囊30 d后,观察其体重,测定其免疫器官指数、脾淋巴细胞增殖能力、小鼠迟发型变态反应,血清溶血素、自然杀伤细胞(NK细胞)活性、抗体生成细胞水平及腹腔巨噬细胞吞噬功能的变化。结果石斛人参蝙蝠蛾姜胶囊中功效成分的含量分别为人参皂甙:1.495 g/100 g、多糖:12.90 g/100 g和腺苷:73.8 mg/100 g;1580 mg/kg组可增强细胞免疫功能(脾淋巴细胞增殖能力和小鼠迟发型变态反应增强)、提高抗体生成细胞水平、提高小鼠巨噬细胞吞噬活性。结论在本实验条件下,石斛人参蝙蝠蛾姜胶囊有增强小鼠免疫功能的作用。

关键词： COVID-19   SARS-CoV-2   RaTG13   intermediate horseshoe bat   ACE2   RBD  

摘要： Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading worldwide, causing a global pandemic. Bat-origin RaTG13 is currently the most phylogenetically related virus. Here we obtained the complex structure of the RaTG13 receptor binding domain (RBD) with human ACE2 (hACE2) and evaluated binding of RaTG13 RBD to 24 additional ACE2 orthologs. By substituting residues in the RaTG13 RBD with their counterparts in the SARS-CoV-2 RBD, we found that residue 501, the major position found in variants of concern (VOCs) 501Y.V1/V2/V3, plays a key role in determining the potential host range of RaTG13. We also found that SARS-CoV-2 could induce strong cross-reactive antibodies to RaTG13 and identified a SARS-CoV-2 monoclonal antibody (mAb), CB6, that could cross-neutralize RaTG13 pseudovirus. These results elucidate the receptor binding and host adaption mechanisms of RaTG13 and emphasize the importance of continuous surveillance of coronaviruses (CoVs) carried by animal reservoirs to prevent another spillover of CoVs.

关键词： SARS-CoV-2   Bat coronavirus RaTG13   Spike protein   Rhinolophus affinis bat ACE2   Host susceptibility   Coronavirus entry  

摘要： Bat coronavirus(CoV)RaTG13 shares the highest genome sequence identity with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)among all known coronaviruses,and also uses human angiotensin converting enzyme 2(hACE2)for virus ***,SARS-CoV-2 is thought to have originated from ***,whether SARS-CoV-2 emerged from bats directly or through an intermediate host remains ***,we found that Rhinolophus affinis bat ACE2(Ra ACE2)is an entry receptor for both SARSCoV-2 and Ra TG13,although the binding of Ra ACE2 to the receptor-binding domain(RBD)of SARSCoV-2 is markedly weaker than that of h *** further evaluated the receptor activities of ACE2 s from additional 16 diverse animal species for Ra TG13,SARS-CoV,and SARS-CoV-2 in terms of S protein binding,membrane fusion,and pseudovirus *** found that the Ra TG13 spike(S)protein is significantly less fusogenic than SARS-CoV and SARS-CoV-2,and seven out of sixteen different ACE2 s function as entry receptors for all three viruses,indicating that all three viruses might have broad host *** note,Ra TG13 S pseudovirions can use mouse,but not pangolin ACE2,for virus entry,whereas SARS-CoV-2 S pseudovirions can use pangolin,but not mouse,ACE2 enter cells *** analysis revealed that residues 484 and 498 in Ra TG13 and SARS-CoV-2 S proteins play critical roles in recognition of mouse and human ACE2 ***,two polymorphous Rhinolophous sinicus bat ACE2 s showed different susceptibilities to virus entry by Ra TG13 and SARS-CoV-2 S pseudovirions,suggesting possible *** results offer better understanding of the mechanism of coronavirus entry,host range,and virushost coevolution.

关键词： COVID-19   SARS-CoV-2   gut microbiota   bat   anti-inflammatory   antiviral  

摘要： Bats are a potential natural reservoir for SARS-CoV-2 virus and other viruses detrimental to *** evidence has shown that,in their adaptation to a flight-based lifestyle,remodeling of the gut microbiota in bats may have contributed to immune tolerance to *** evidence from bats provides profound insights into the potential influence of gut microbiota in COVID-19 disease in ***,we highlight recent advances in our understanding of the mechanisms by which the gut microbiota helps bats tolerate deadly viruses,and summarize the current clinical evidence on the influence of gut microbiota on the susceptibility to SARS-CoV-2 infection and risk of COVID-19 leading to a fatal *** addition,we discuss the implications of gut microbiota-targeted approaches for preventing infection and reducing disease severity in COVID-19 patients.

关键词： Heparan sulfate   Disaccharide composition   Molecular weight   SARS-CoV-2 virus   Spike protein RBD  

摘要： Severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) has resulted in a pandemic and continues to spread at an unprecedented rate around the world. Although a vaccine has recently been approved, there are currently few effective therapeutics to fight its associated disease in humans, COVID-19. SARS-CoV-2 and the related severe acute respiratory syndrome (SARS-CoV-1), and Middle East respiratory syndrome (MERS-CoV) result from zoonotic respiratory viruses that have bats as the primary host and an as yet unknown secondary host. While each of these viruses has different protein-based cell-surface receptors, each rely on the glycosaminoglycan, heparan sulfate as a co-receptor. In this study we compare, for the first time, differences and similarities in the structure of heparan sulfate in human and bat lungs. Furthermore, we show that the spike glycoprotein of COVID-19 binds 3.5 times stronger to human lung heparan sulfate than bat lung heparan sulfate.