Polymorphisms in the S1 spike glycoprotein of Arkansas-type infectious bronchitis virus (IBV) show differential binding to host tissues and altered antigenicity.
Sequencing avian infectious bronchitis virus spike genes re-isolated from vaccinated chicks revealed that many sequence changes are found on the S1 spike gene. In the ArkDPI strain, Y43H and ∆344 are the two most common changes observed. This study aims to examine the roles of Y43H and ∆344 in selection in vivo. Using recombinant ArkDPI S1 proteins, we conducted binding assays on chicken tracheas and embryonic chorioallantoic membrane (CAM). Protein histochemistry showed that the Y43H change allows for enhanced binding to trachea, whereas the ArkDPI S1 spike with H43 alone was able to bind CAM. Using Western blot under denaturing conditions, ArkDPI serotype-specific sera did not bind to S1 proteins with ∆344, suggesting that ∆344 alters antigenicity of S1. These findings are important because they propose that specific changes in S1 enhances virus fitness by more effective binding to host tissues (Y43H) and by evading a vaccine-induced antibody response (∆344).
Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, 953 College Station Road, Athens, GA 30602, USA. Electronic address: cmleyson@uga.edu.
Christina
C
Leyson
Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, 953 College Station Road, Athens, GA 30602, USA. Electronic address: mfranca@uga.edu.
Monique
M
França
Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, 953 College Station Road, Athens, GA 30602, USA. Electronic address: mjackwoo@uga.edu.
Mark
M
Jackwood
Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, 953 College Station Road, Athens, GA 30602, USA; Department of Poultry Science, College of Agricultural and Environmental Sciences, University of Georgia, 953 College Station Road, Athens, GA 30602, USA. Electronic address: brian89@uga.edu.
Brian
B
Jordan
D000595:Amino Acid Sequence; D000818:Animals; D000940:Antigenic Variation / Q000235:genetics*; D000956:Antigens, Viral / Q000235:genetics* / Q000276:immunology*; D002645:Chickens; D001351:Infectious bronchitis virus / Q000502:physiology*; D009154:Mutation; D011110:Polymorphism, Genetic; D011485:Protein Binding / Q000276:immunology; D011993:Recombinant Fusion Proteins; D064370:Spike Glycoprotein, Coronavirus / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
D000956:Antigens, Viral; D011993:Recombinant Fusion Proteins; D064370:Spike Glycoprotein, Coronavirus
Arkansas-type vaccine; Coronavirus spike; Infectious bronchitis virus; S1 spike; Spike glycoprotein