Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada, M5S 1A8.
Published: November 2017
AI Article Synopsis
Article Abstract
RNA viruses are characterized by a high mutation rate, a buffer against environmental change. Nevertheless, the means by which random mutation improves viral fitness is not well characterized. Here we report the X-ray crystal structure of the receptor-binding domain (RBD) of the human coronavirus, HCoV-229E, in complex with the ectodomain of its receptor, aminopeptidase N (APN). Three extended loops are solely responsible for receptor binding and the evolution of HCoV-229E and its close relatives is accompanied by changing loop-receptor interactions. Phylogenetic analysis shows that the natural HCoV-229E receptor-binding loop variation observed defines six RBD classes whose viruses have successively replaced each other in the human population over the past 50 years. These RBD classes differ in their affinity for APN and their ability to bind an HCoV-229E neutralizing antibody. Together, our results provide a model for alphacoronavirus adaptation and evolution based on the use of extended loops for receptor binding.
Background: In recent years, the prevalence and incidence of porcine epidemic diarrhea virus (PEDV) infection have been on the rise. The occurrence of multiviral infections and recombination mutations has led to accelerated viral evolution and reduced vaccine efficacy. In the present study, a PEDV strain was isolated from a pig farm (Chongqing Province, China) with an outbreak of porcine diarrhea, and its S gene was found to be recombinant.
Porcine epidemic diarrhea virus (PEDV) is a major disease affecting pigs, causing high mortality in piglets and substantial economic impacts in the industry.
Three PEDV strains (HN-1, HN-2, SC2023) were isolated in Sichuan and Henan, with HN-1 showing significant growth in cell cultures and unique genetic mutations that may lower its pathogenicity.
HN-1's ability to adapt to cell culture makes it a valuable candidate for studying PEDV and potentially developing safer vaccines.
Scientists studied a virus called PEDV that makes pigs sick, which has caused big problems for pig farmers in many countries.
They tested two strains of the virus in a lab to see how they changed over time and found that one strain had a part of its gene missing, which made it less harmful.
When mother pigs were given a vaccine with this less harmful strain, it helped make their piglets more resistant to other types of the virus.
Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, Zhejiang Province, China.
Porcine epidemic diarrhea virus (PEDV) causes high mortality in piglets, making it crucial to monitor its mutations for vaccine development.
Two PEDV strains (ZJ2022 and ZQ2022) were identified, with ZQ2022 being a recombinant strain and showing more severe pathogenicity compared to ZJ2022.
The study indicates ZJ2022's unique genetic modification may enhance its potential as a vaccine candidate due to its lower pathogenicity and stronger cellular adaptation.
Coronavirus stands for a large family of viruses characterized by protruding spikes surrounding a lipidic membrane adorned with proteins. The present study explores the adhesion of transmissible gastroenteritis coronavirus (TGEV) particles on a variety of reference solid surfaces that emulate typical virus-surface interactions. Atomic force microscopy informs about trapping effectivity and the shape of the virus envelope on each surface, revealing that the deformation of TGEV particles spans from 20% to 50% in diameter.
