Effect of acyclovir on HHV6/HHV8?

[Giovanni Maga]

In article <3pmdfc$1f0a at bigblue.oit.unc.edu>, ilva at email.unc.edu (Jeffrey
Johnston) wrote:

> What would be interesting would be to validate some of the HIV-HHV inter-
> action hypotheses by looking for quantitative evidence of HHV in HIV-infected 
> persons receiving one of the anti-herpes drug. If, for example, the theory 
> that HHV-8 is associated with Kaposi's is true, then is treatment with 
> acyclovir (or related drugs) associated with a decreased occurrence of this 
> opportunistic infection? 
>	____________________________(snip)_________________________
> : Mike

I do not know which class HHV-8 belongs to (alpha, beta or gamma) neither
if anyone knows anything about its infectious cycle (BTW, did they isolate
virions or simple DNA sequences? I have to look it up). But I would make a
general comment. As you point out, there are usually massive HSV-1 and 2 as
well CMV infections in AIDS patients with severe symptomathology, which can
substantially contribute to the worsening of the patient's health. Thus, a
beneficial effect of ACV (or DHPG) treatment could be hardly taken as an
indication of a role of any other herpesvirus in AIDS ethiology. BTW, I do
not know if there is a productive infection by HHV-8 and of which entity.
ACV is effective only in the lytic infections (when the viral DNA pol is
doing its job). Moreover, before taking ACV as an hallmark it should be
shown at least in vitro that HHV-8 is sensitive (since it is not a
consequence of the fact that it's an herpesvirus). Then, it must be
evaluated if in vivo the targeted cells are as well permissive for ACV
uptake and activation (phosphorylation to ACVTP).
Probably it is a little bit too early for such an evaluation, but I find
the scenario of a possible synergism of HIV and some herpesviruses (more
likely a gamma-one like HHV-6) very interesting.
G.Maga
maga at vetbio.unizh.ch