From:
sukie crandall
Date: 2005-07-21 13:11:25 UTC
Subject: some ADV stuff
To: ferrethealth@smartgroups.com
Message-id: <39A3CDA8-92F5-44C3-9013-B7946FACB0B0@optonline.net>
Subject: THERE IS NOT AN EFFECTIVE VACCINE YET. ADV besides =
at UGA (just in case anyone is curious what searching brings up)
Date: July 21, 2005 8:47:28 AM EDT
When Danee has a chance to be back on line for ferret stuff she will =
be able to tell you more about UGA work. Meanwhile, you can look at =
her past series of posts in archives such as those of the FML and =
FHL. If the FML ones aren't up to that date, yet, then you should be =
able to find them elsewhere (Maybe someone here knows where to see =
the entire series.) or use the dates of the partial series in the FHL =
Archives to work back to the digest numbers for the FML and then use =
the GET FERRET nnnn feature to get those particular digests for =
yourself.
http://www.usu.edu/iar/Brochure/brochure.html
USU Institute for Antiviral Research biographies include:
>Dr. Dale L. Barnard: ...Dr. Barnard=92s research interests are in =
the elucidation of the biochemical cytotoxicity and mechanisms of =
antiviral >action of new antiviral agents. A major thrust of his =
research is to pinpoint a viral enzyme which could be used as a =
target for developing >selective and specific antiviral drugs. He =
has been instrumental in studying methods by which mink aleutian =
virus disease can be treated.
BUT I think (relying on memory on this so that can be faulty) that he =
may have done that work in what *may* now be a defunct national =
persistent diseases lab (the budget cutbacks have hit some very good =
places with all of the huge war debt and some labs have been =
destroyed and others were mentioned in the ax's line up in the =
current budget) so don't know if he now has funds which allow him to =
currently work on Aleutians. Still, he and the people in UGA should =
have the info sought, as should ADV researchers elsewhere. Also, I =
may be confusing him with someone else so he might have current work =
going on into ADV.
http://www.pubmedcentral.nih.gov/articlerender.fcgi? =
artid=3D114691&tools=3Dbot
includes:
>Attempts to protect adult mink with capsid-based ADV vaccines have =
uniformly failed, even though vaccinated animals develop antiviral =
>antibodies (1, 49, 52). Indeed, upon challenge, vaccinated animals =
suffer a hyperacute disease with enhanced tissue lesions (1, 52)... =
>Whereas virus neutralization by antibody may afford protection from =
infection, ADE facilitates the infection of macrophages that is =
central >to the resulting immune disorder (15, 29, 35). Antibodies to =
VP2:428-446 have been demonstrated in ADV-infected adult mink (28) =
and, >if these antibodies function to mediate both ADE and =
neutralization in vivo, any protective effect might be counteracted =
or supervened. >Thus, our results provide possible explanations for =
the failure of capsid-based ADV vaccines (1, 52).
There is more in this and further paragraphs on possible alternative =
possible vaccine approaches beyond what currently exists, but the UGA =
work is several years more recent, of course.
Notice that work is ongoing because there is not an effective =
vaccine, and when that category of vaccines above was tried, although =
the mink in the study did develop antibodies it is not shown that =
they provided much if anything in the way of protection, and once =
they caught the disease the result of was that the disease itself was =
actually worsened.
This British study is a few years older:
http://www.pubmedcentral.nih.gov/articlerender.fcgi? =
artid=3D112773&tools=3Dbot
These may interest the persistent reader into virology:
http://jvi.asm.org/cgi/content/full/75/22/11116
and
http://jvi.asm.org/cgi/content/full/73/8/6882
which is a more recent British study includes
>Disease caused by ADV differs significantly from that caused by =
other parvoviruses in which infection leads to a protective host =
>response. For ADV, the presence of the capsid elicits a host =
response that actually contributes to the disease process (50, 51). =
Recent >studies, in which the ADV capsid proteins were expressed in a =
series of nonoverlapping fragments, indicate that the unusual =
antibody >response is targeted to specific epitopes (19).
and specific to your question:
>The ADV-G VP2 sequence is 38% identical to CPV at the amino acid level
and more in the discussion section such as
>It is noteworthy that parvoviruses CPV, FPV, and B19, which can all =
be neutralized by a host-antibody response, lack the ADV mounds > =
(Fig. 4 and 6). The unusual pathogenicity of ADV might arise if the =
mounds act as immunodominant decoys that somehow prevent a =
>protective response from being generated during infection.
See also the paragraph beginning:
>Economic losses to the fur industry as a result of ADV infection of =
farmed mink are mainly a consequence of the unusual pathogenicity >of =
ADV, in which infectivity is enhanced by capsid-antibody and capsid =
protein fragment-antibody complexes (1, 50, 51) formed during >an =
infection. This property has thwarted numerous attempts at particle- =
based vaccine development. Current strategies for global >development =
of vaccines against parvoviruses are focused on the use of virus-like =
particles or peptides...
There is more but I am out of time so just use these to get ideas of =
places to search, keywords, phrases to search on, etc.
-- Sukie (not a vet)
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