title: Bacterial expression of antigenic sites A and D in the spike protein of transmissible gastroenteritis virus and evaluation of their inhibitory effects on viral infection.
abstract: The spike (S) protein is a key structural protein of coronaviruses including, the porcine transmissible gastroenteritis virus (TGEV). The S protein is a type I membrane glycoprotein located in the viral envelope and is responsible for mediating the binding of viral particles to specific cell receptors and therefore specific cell types. It is also an important immune target for the host in neutralizing the virus. Four antigenic sites A, B, C, and D that reside near the N-terminal domain have been defined in the S protein. Of these, the region encoding antigenic sites A and to a lesser extent D, herein defined as S-AD, are most critical in eliciting host neutralizing antibodies. Herein, we enzymatically amplified, cloned, and expressed the S-AD fragment from TGEV in the prokaryotic expression vector, pET-30a. Maximum protein expression was achieved at 30°C over a 5-h period post-induction. Rabbit polyclonal antiserum was generated using recombinant S-AD (rS-AD) protein. In contrast to prior studies showing no activity with bacterially produced S protein, results indicated that polyclonal serum recognized TGEV-infected cells and reduced infection by 100%. Furthermore, the truncated rS-AD peptide was able to bind to the surface of cells from swine testes in a competitive manner and completely inhibit viral infection.
authors.affiliation: College of Veterinary Medicine, Northeast Agricultural University, Harbin, China.
authors.forename: Fandan
authors.initials: F
authors.lastname: Meng
authors.forename: Zeping
authors.initials: Z
authors.lastname: Zhao
authors.forename: Guangxing
authors.initials: G
authors.lastname: Li
authors.forename: Siqingaowa
authors.initials: S
authors.lastname: Suo
authors.forename: Na
authors.initials: N
authors.lastname: Shi
authors.forename: Jiechao
authors.initials: J
authors.lastname: Yin
authors.forename: Dante
authors.initials: D
authors.lastname: Zarlenga
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Ren
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D000956:Antigens, Viral / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002460:Cell Line; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005761:Gastroenteritis, Transmissible, of Swine / Q000517:prevention & control* / Q000821:virology; D015870:Gene Expression; D011485:Protein Binding; D011817:Rabbits; D013552:Swine; D005760:Transmissible gastroenteritis virus / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D000956:Antigens, Viral; D014764:Viral Proteins; C064484:spike protein S, Transmissible gastroenteritis virus