Abstract
Vaccinia virus (VV) infection produces several types of virus particle called intracellular mature virus (IMV), intracellular enveloped virus (IEV), cell-associated enveloped virus (CEV) and extracellular enveloped virus (EEV). Some cellular antigens are associated with EEV and these vary with the cell type used to grow the virus. To investigate if specific cell antigens are associated with VV particles, and to address the origin of membranes used to envelope IMV and IEV/CEV/EEV, we have studied whether cell antigens and foreign antigens expressed by recombinant VVs are incorporated into VV particles. Membrane proteins that are incorporated into the endoplasmic reticulum (ER), intermediate compartment (IC), cis/medial-Golgi, trans-Golgi network (TGN) or plasma membrane were not detected in purified IMV particles. In contrast, proteins present in the TGN or membrane compartments further downstream in the exocytic pathway co-purify with EEV particles when analysed by immunoblotting. Immunoelectron microscopy found only low levels of these proteins in IEV, CEV/EEV. The incorporation of foreign antigens into VV particles was not affected by loss of individual IEV or EEV-specific proteins or by redirection of B5R to the ER. These data suggest that (i) host cell antigens are excluded from the lipid envelope surrounding the IMV particle and (ii) membranes of the ER, IC and cis/medial-Golgi are not used to wrap IMV particles to form IEV. Lastly, the VV haemagglutinin was absent from one-third of IEV and CEV/EEV particles, whereas other EEV antigens were present in all these virions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.