Do enveloped viruses contain MHC molecules?
December 10, 2008 8:11 PM Subscribe
Yo, immunologists/virologists!
Do viral envelopes ever contain actual allogeneic MHC molecules? That is, if person X gets infected by an enveloped virus and passes it on to person Y, will person Y get some of X's MHCs?
Just idle musing and hypothesis forming. Research being confounded by the many articles about MHC mimcry in viral envelopes. Thanks!
Just idle musing and hypothesis forming. Research being confounded by the many articles about MHC mimcry in viral envelopes. Thanks!
Best answer: It looks like there's information out there about specific viruses: HIV-1, for instance. Summary: around 50-63 per virion.
posted by pullayup at 5:27 AM on December 11, 2008
posted by pullayup at 5:27 AM on December 11, 2008
Crap, that's only Class II, though it looks like Class I is actively recruited too, and may be necessary for generation of "entry-competent viral particles."
posted by pullayup at 5:37 AM on December 11, 2008
posted by pullayup at 5:37 AM on December 11, 2008
Best answer: From what I can find (and remember), there do not appear to be many or any MHC molecules in HSV envelopes. There was a paper that came out this September that examined virion protein content by mass-spectrometry. This list could be incomplete due to a cell type dependency on what gets incorporated (in the paper, they purified virions from HeLa cells, which might differ from virus purified from another cell line that isn't totally screwed up like HeLas are) or limitations in the method used. A quick look on Pubmed and through Fields Virology, however, doesn't really turn up any other info on this.
The lack of MHC in an HSV envelope would make sense, though, because the HSV protein, ICP47, actively prevents TAP1/2 from loading antigen onto MHC I and, if I remember right, antigen loading is necessary for MHC I to migrate to the plasma membrane.
posted by The Bishop of Turkey at 7:53 AM on December 11, 2008
The lack of MHC in an HSV envelope would make sense, though, because the HSV protein, ICP47, actively prevents TAP1/2 from loading antigen onto MHC I and, if I remember right, antigen loading is necessary for MHC I to migrate to the plasma membrane.
posted by The Bishop of Turkey at 7:53 AM on December 11, 2008
Okay, so there is something else on Pubmed about this: HSV interferes with the expression of MHC II cofactors and prevents cell surface expression of MHC II.
posted by The Bishop of Turkey at 7:56 AM on December 11, 2008
posted by The Bishop of Turkey at 7:56 AM on December 11, 2008
This thread is closed to new comments.
As I understand things, part of the purpose of the envelope is to help the virus identify as 'self', evading the immune system.
wiki
The envelopes are typically derived from portions of the host cell membranes (phospholipids and proteins), but include some viral glycoproteins.
posted by Orange Pamplemousse at 8:24 PM on December 10, 2008