Molecular Mimicry between Fc Receptor and S Peplomer Protein of Mouse Hepatitis Virus, Bovine Corona Virus, and Transmissible Gastroenteritis Virus

Abstract

We have previously demonstrated molecular mimicry between the S peplomer protein of mouse hepatitis virus (MHV) and Fc gamma R (Fc gamma R). A monoclonal antibody (MAb) to mouse Fc gamma R (2.4G2 anti-Fc gamma R MAb), purified rabbit immunoglobulin, but not their F(ab')2 fragments, as well as mouse and rat IgG, immunoprecipitated (1) recombinant S peplomer protein expressed by a vaccinia virus recombinant in human, rabbit, and mouse cells, and (2) natural S peplomer protein from cells infected with several strains of MHV and MHV escaped mutants. We report here results of studies documenting molecular mimicry between Fc gamma R and S peplomer protein of viruses representing three distinct antigenic subgroups of the Coronaviridae. We have shown a molecular mimicry between the S peplomer protein of bovine corona virus (BCV) and Fc gamma R. The 2.4G2 anti-Fc gamma R MAb, rabbit IgG, but not its F(ab')2 fragments, as well as homologous bovine serum, free of anti-BCV antibodies, immunoprecipitated S peplomer protein of BCV (Mebus strain). In contrast, we did not find molecular mimicry between S peplomer protein of human corona virus (HCV-OC43) and Fc gamma R. Although the OC43 virus belongs to the same antigenic group as MHV and BCV, MAb specific for human Fc gamma RI or Fc gamma RII and purified human IgG1, IgG2, and IgG3 myeloma proteins did not immunoprecipitate the S peplomer protein from HCV-OC43-infected RD cells. In addition, we did demonstrate molecular mimicry between the S peplomer protein of porcine transmissible gastroenteritis virus (TGEV) and Fc gamma R. TGEV belongs to the second antigenic subgroup of coronaviridae.(ABSTRACT TRUNCATED AT 250 WORDS)

Virus complement evasion strategies

“…A third antigenic subgroup contains the infectious bronchitis virus (IBV) as an important member. For HCV and IBV, however, Fc receptor activity of the spike protein could not be demonstrated (Oleszak, 1994;Oleszak et al, 1995).…”

Identification of novel functional regions within the spike glycoprotein of MHV-A59 based on a bioinformatics approach

“…This Fc binding activity is also exhibited by the related type 2a betacoronavirus, bovine coronavirus (BCoV) S protein (Oleszak et al, 1995). However, the human coronavirus OC43 (HCoV-OC43), a virus closely related to BCoV, did not exhibit molecular mimicry of Fc␥RII/RIII in that it was not reactive with the 2.4G2 monoclonal antibody (Oleszak et al, 1995).…”

“…The MHV S protein behaved as a molecular mimic of the host murine Fc␥ receptor (mFc␥RII/RIII) in that it bound IgG in an Fc dependent manner, was immunoprecipitated by the 2.4G2 anti-Fc␥RII/RIII monoclonal antibody, and the Fc binding activity of S protein was expressed on the plasma membrane of infected cells (Oleszak et al, 1990(Oleszak et al, , 1992. This Fc binding activity is also exhibited by the related type 2a betacoronavirus, bovine coronavirus (BCoV) S protein (Oleszak et al, 1995). However, the human coronavirus OC43 (HCoV-OC43), a virus closely related to BCoV, did not exhibit molecular mimicry of Fc␥RII/RIII in that it was not reactive with the 2.4G2 monoclonal antibody (Oleszak et al, 1995).…”

Identification and characterization of a Fc Receptor activity on the Toxoplasma gondii tachyzoite

“…Immunoglobulin Binding Proteins (IBP) are part of the cell membrane of both pro‐ and eukaryotes. They have been demonstrated on the surface of different micro‐organisms such as bacteria (reviewed in Boyle 1990) and parasites (see below), as well as on the surface of cells infected with viruses (reviewed in Oleszak et al . 1995).…”