Nipah virus (NiV), a zoonotic paramyxovirus belonging to the genus Henipavirus, is classified as a Biosafety Level-4 pathogen based on its high pathogenicity in humans and the lack of available vaccines or therapeutics. Since its initial emergence in 1998 in Malaysia, this virus has been reported in Asia, Africa, and the South Pacific Ocean. NiV has a wide range of hosts, from its natural reservoir Pteropid bats to humans, horses, dogs, cats, cows, and pigs. NiV spreads from bats to humans through two main pathways, intermediate hosts (pigs and horses) and food-borne transmission via date palm sap contaminated with the saliva or urine of fruit bats. In this issue, Sun et al. reviewed the recent studies on the geographical and phylogenetic properties, transmission, and protein structure and function of NiV. The cover image is provided courtesy of Bangyao Sun and Di Liu. (See Page 385-393 for details).
Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a zoonotic pathogen capable of causing severe respiratory disease in humans. Although dromedary camels are considered as a major reservoir host, the MERS-CoV infection dynamics in camels are not fully understood. Through surveillance in Pakistan, nasal (n=776) and serum (n=1050) samples were collected from camels between November 2015 and February 2018. Samples were collected from animal markets, free-roaming herds and abattoirs. An in-house ELISA was developed to detect IgG against MERS-CoV. A total of 794 camels were found seropositive for MERS-CoV. Prevalence increased with the age and the highest seroprevalence was recorded in camels aged > 10 years (81.37%) followed by those aged 3.1-10 years (78.65%) and ≤ 3 years (58.19%). Higher prevalence was observed in female (78.13%) as compared to male (70.70%). Of the camel nasal swabs, 22 were found to be positive by RT-qPCR though with high Ct values. Moreover, 2,409 human serum samples were also collected from four provinces of Pakistan during 2016-2017. Among the sampled population, 840 humans were camel herders. Although we found a high rate of MERS-CoV antibody positive dromedaries (75.62%) in Pakistan, no neutralizing antibodies were detected in humans with and without contact to camels.
Cyclophilin A (CypA,亲环素A)是一种肽基脯氨酰顺反异构酶,能够与A型流感病毒M1蛋白相互作用,通过调控M1的泛素-蛋白酶体途径的降解来抑制病毒的复制。然而,CypA调控M1蛋白泛素化的机制尚不清楚。我们发现 E3连接酶AIP4能够促进M1在K102和K104位点的泛素化,并加速M1的泛素-蛋白酶体途径的降解。K102R/K104R突变导致重组病毒无法拯救,表明M1在K102和K104位点的泛素化是病毒复制所必需的。进一步研究表明,CypA能够破坏AIP4与M1的相互作用,抑制AIP4介导的M1泛素化。更为重要的是,K102R/K104R突变及CypA均能够抑制M1的出核,表明CypA通过调控AIP4介导的M1在K102和K104位点的泛素化抑制M1的出核,进而影响流感病毒的复制。本研究揭示了CypA通过调控M1泛素化来影响流感病毒复制的机制。
Marine mammals are widely distributed and can be found almost in all coastal waters and coastlines around the world. The interface areas between marine and terrestrial environments provide natural habitats for aquatic and semiaquatic mammals as well as for reservoir species of avian influenza viruses (AIV) (Runstadler et al. 2013). Previous studies showed that wild aquatic birds, the natural reservoir of AIV, are able to transmit the virus to various mammals, including seals, swine, horses, muskrats, and humans (Webster et al. 1992; Reperant et al. 2009; Gulyaeva et al. 2017). Close contacts between sea mammals and wild birds on breeding-grounds could promote both interspecies transmission of AIV and virus establishment in a new host (Fereidouni et al. 2014). Various AIV subtypes (A/seal/ Massachusetts/80(H7N7), A/Seal/MA/133/82(H4N5), A/Seal/MA/3807/91(H4N6), A/Seal/MA/3911/92(H3N3), A/harbour seal/Mass/1/2011(H3N8) and A/harbor seal/NL/ PV14-221_ThS/2015(H10N7) etc.) have been isolated from different species of marine mammals during the last 30 years. AIV isolated from marine mammals and wild birds are closely related, which suggests that wild birds are the major source of AIV infection (Fereidouni et al. 2014; Bodewes et al. 2015). In addition, AIV can cross species barrier and replicate well in experimental mammals without prior adaptation (Driskell et al. 2012).
Joel Dudley及其同事在神经学领域国际顶级杂志《Neuron》7月11日在线发表了一项最新研究结果显示了,HHV-6A和HHV-7均可能是阿兹海默症AD的重要致病因子。然而,鉴于各种生物学和相关技术局限性,我们回顾了仅目前数据情况下确定HHV-6A和HHV-7感染与AD之间病因关系的复杂性,并着重展望了未来后续工作潜在的研究方向。