Cooperation between transmissible gastroenteritis coronavirus (TGEV) structural proteins in the in vitro induction of virus-specific antibodies

Abstract

Following infection of haplotype defined NIH-miniswine with virulent transmissible gastroenteritis coronavirus (TGEV), isolated mesenteric lymph node CD4+ T-cells mounted a specific proliferative response against infectious or inactivated purified virus in secondary in vitro stimulation. A specific, dose-dependent response to the three major recombinant viral proteins: spike (S), membrane (M), and nucleoprotein (N), purified by affinity chromatography, was characterized. Induction of in vitro antibody synthesis was analyzed. The purified recombinant viral proteins induced the in vitro synthesis of neutralizing TGEV-specific antibodies when porcine TGEV-immune cells were stimulated with each of the combinations made with two of the major structural proteins: S + N, S + M, and to a minor extent with M + N, but not by the individual proteins. S-protein was dissociated from purified virus using NP-40 detergent and then micellar S-protein oligomers (S-rosettes) were formed by removing the detergent. These occurred preferentially by the association of more than 10 S-protein trimmers. These S-rosettes in collaboration with either N or M-proteins elicited TGEV-specific antibodies with titers up to 84 and 60%, respectively, of those induced by the whole virus. N-protein could be partially substituted by a 15-mer peptide that represents a T helper epitope previously identified in N-protein (Antón et al. (1995)). These results indicate that the induction of high levels of TGEV-specific antibodies requires stimulation by at least two viral proteins, and that optimum responses are induced by a combination of S-rosettes and the nucleoprotein.

Development of reverse transcription loop-mediated isothermal amplification for rapid detection of porcine epidemic diarrhea virus

“…Coronavirus comprises three major viral structural proteins: spike (S, 180-220 kDa), membrane (M, 27-32 kDa), and nucleocapsid (N, 55-58 kDa) proteins [5,6]. The S protein is a major viral antigen, binds to a cellular receptor for virus attachment to enter target cells and mediates viral attachment to target cells [7][8][9][10][11][12][13]. The M protein is a trans-membrane protein [14] and it is involved in the assembly process of viral nucleocapsid and membrane [15,16].…”

Severe acute respiratory syndrome vaccine efficacy in ferrets: whole killed virus and adenovirus-vectored vaccines

“…A successful SARS vaccine could be used prophylactically to protect healthcare workers, laboratory personnel and others in high-risk areas. No vaccines are currently licensed for any of the human CoV, but experimental vaccines have been produced for a number of CoVs for use in chickens, cattle, dogs, cats and swine (Anton et al, 1996;Cavanagh, 2003;Olsen et al, 1993).…”

“…A DNA-based vaccine (Yang et al, 2004), a modified Ankara vaccinia virus (Bisht et al, 2004) and a recombinant attenuated parainfluenza virus have been shown to induce neutralizing antibodies and reduce pulmonary SARS-CoV replication. Studies from other animal CoV vaccines have shown that the CoV nucleocapsid (N) protein may represent another antigen candidate for vaccine development (Anton et al, 1996;Olsen, 1993). Although antibodies to CoV N proteins have no virus-neutralizing activity, there is evidence that the protein may provide protection in vivo by induction of cell-mediated immunity, although it has also been suggested to induce eosinophilic infiltrates resulting in immunopathology (Deming et al, 2006;Enjuanes et al, 1995;Stohlman et al, 1995;Wesseling et al, 1993).…”

“…The aetiological agent of SARS has been identified as a novel human CoV by sequencing of its genome (Marra et al, 2003;Rota et al, 2003) and by experimental infection of macaques to fulfil Koch's postulates (Fouchier et al, 2003). It is of particular concern as a zoonosis because it can replicate in a large number of animals including cats, pigs, ferrets, foxes, monkeys and rats (Chen et al, 2005; et al, 1996;Olsen, 1993). Although antibodies to CoV N proteins have no virus-neutralizing activity, there is evidence that the protein may provide protection in vivo by induction of cell-mediated immunity, although it has also been suggested to induce eosinophilic infiltrates resulting in immunopathology (Deming et al, 2006;Enjuanes et al, 1995; Stohlman et al, 1995;Wesseling et al, 1993).…”

Porcine gastroenteric viruses: pathogenesis and protection

“…The production of these antigenic complexes has been well documented for TGEV (Fig. 5B) (Anton et al, 1996). Similarly, purified complete viruses could in principle be used as vaccines to protect against PEDV by oral immunization.…”