Can we make anti-viruses(anti-virals)?

Since we got anti-biotics and anti-fungals to fight bacterial and fungus infections, can we make anti-virals that will fight viruses? I realize the structure of viruses are much smaller and different that bacteria and fungi but with our brilliant scientist we have to have come up with something by now, if not at hopefully sometime in the near future.

Anti-virals already exist... AZT, for example. But this particular area of biotechnology is likely to see an increase in funding simply because of the currently en vogue bioterrorist agenda. Viruses such as West Nile, SARS, and even the good old flu are starting to become more of a threat, or at least are perceived as more of a threat now as well.

In any case the design of anti-virals tends to differ than say an antibiotic. Anti-virals are likely to synthetic molecules that are analogous to, but hopefully an even better 'fit' than the viruses actual target. AZT is one such example. While not a better fit per se, the molecule is capable of being inserted into a viral genome by virtue of the viral polymerase enzyme. Once inserted it stops viral genome synthesis. Other such molecules with different targets are being developed. For example, I know a guy who's overproducing a version of CD4, the protein that HIV docks to. In theory, a system saturated with CD4 could outcompete HIV's natural binding site on the T cells and inhibit further infection. This of course could have consequences of its own. In short though, the design of anti-virals is becoming a high tech business, involving lots of molecular modeling, and actual protein structural studies. Then of course the molecule has to be FDA approved, so it's a huge process.

I have always thought AZT and read that did more harm than good and it isnt a very effective anti-viral and all it does is slow the spread of the virus instead of curing it. I was hoping there was something better out there.

Viruses integrate into a host genome; so, short of genetically engineering the viral genome out of the host via some currently unknown process, we are limited to attempting to deal with viruses via the previously described mechanisms.

Anyway, AZT would be described as an infant drug in a field that is going to increase exponentially in the coming decades. Drug development isn't an easy process.

well some aussie scientists modified a mosquito virus so it kills cancer cells in mice.
So this is kind of like what you're talking about I think?

Very good point! There are so many levels and test that have to be ran in order for a new drug to come out on the market and even then it has it's side effects. The human body is a very mysterious thing. Let's not forget that viruses also have a tendency to mutate which makes it hard for any one specific medicine to be effective over time. This is why for example we have a new flu vaccine every year.

No, only Retro-viruses normally integrate into the host genome. The two enzymes that only retro-viruses contain are reverse transcriptase (Creates a DNA template of the RNA virus) and integrase (Takes the DNA template and integrates into the host DNA).
Other types of viruses can integrate, but its normally a random and relatively rare event (if you infuse cells with enough bits of random DNA in fact, you can eventually get those random bits to integrate too!)
Frankly, I'm very happy that only retro-viruses integrate, I'd hate to have numerous types of flus and colds permanently attached to my genome!!!
lol
Back to anti-virals:
The main reason why we don't have many effective anti-viral therapies is because viruses use the host machinery to replicate themselves.
With antibiotics, they take advantage of the different metabolic pathways and different envelope proteins to only kill bacteria rather than human cells. With viruses, this is much more difficult.
For example, penicillin and all other beta-lactams work by interfering with the synthesis of peptidoglycan, a cell wall protein found only in bacteria (As opposed to us: YAY!)
So how do we stop viruses? Unfortunately we don't very well. AZT as you mentioned before functions as a nucleoside analogue, it is picked up by reverse transriptase and placed in the growing DNA viral chain. It however, isn't a 'real' nucleoside (It's like thymidine but not really) and its addition to the chain causes its termination.
However, gamma DNA polymerase (A human enzyme) also picks up AZT and it is this that (most likely) causes the poor side effect profiles.
Another good example is Acyclovir, the first anti viral ever made. It functions in a much similar way to AZT (its also a nucleoside analogue), except it isn't preferentially taken up by reverse transcriptase, its preferred by herpes simplex and varicella-zoster DNA polymerases.
As you can see, with viruses it is much more difficult to differentiate between the virus and the host.

[edit on 18-4-2005 by Gymboy]

Untrue. All viruses are capable of integrating into host genomes; RT and integrase are not required for integration, both random insertion and homologous recombination are known mechanisms. Viruses have two different and distinct life-cycles... most viruses anyway... the lytic phase and lysogenic phase. Both phases require integration into host genomes. And you do in fact have numerous viral genomes residing in various somatic cells.

Great examples of incorporation of non-retroviral genomes into host somatic cells include: varicella-zoster, which causes chicken pox; both herpes viruses 1 and 2; cytomegalovirus, which most of us have; Epstein-Barr virus, and hepatitis B. All of these are double stranded DNA viruses, not retroviruses, and all incorporate into host genomes.



Hence the description nucleoside analog.



[edit on 18-4-2005 by mattison0922]

ive always wondered if anyone has ever tried modifiying a cell, or something like that, to mutate with the virus. You know, a symbiotic relationship with the virus, which grows with it.. who knows.

I know. People are active trying to change or modify genomes using viruses... been doing it for years.

Mattison:
You are correct that all viruses can integrate (I mentioned that in my first post) However, I was only making that point because your earlier reply implied that viruses integrate on a regular basis (They most certainly do not!!!!)
As an example, HPSV does NOT normally integrate! Rather, the (lifelong? Nobody is really sure yet) effects of the virus occur simply because the virus is able to survive in a stable state inside the neural cell, but NOT as a part of the genome!
In addition: The lytic and lysogenic phases are phases that distinctly only affect prokaryotes! (ie bacteria) Using this as an example for integration has nothing to do with how viruses affect eukaryotes (such as us)

Hmmmm.... apparently I need to go back an review some basic virology. It's been a while. But since I have your attention: Lytic and Lysogenic phases only are relevant for Phages? Really? Certainly, I am aware that HIV, for example, buds off from infected T-cells, and while it doens't lyse the cell per se. It certainly does kill off large numbers of T-cells. Perhaps then you can also explain to me the way in which an RNA virus like influenza infects. Given that it's a dsRNA virus (pretty sure, but doesn't change too much if it's not), how does the naked genetic material make it into the nucleus to produce RNA if it's not incorporated into the genome. Doesn't dsRNA provoke a massive interferon response resulting in degradation of RNA? I thought viruses more or less had to integrate.

I was somewhat suspicious of this statement. While it's been a long time since I've taken virology, I didn't think my recollection would be this far off. And it wasn't. I spoke to a virologist colleague of mine who informed me that most if not all viral life cycles are classified as lytic or lysogenic... this is the case even though most animal viruses don't technically lyse cells, the life-cycle is still referred to as lytic.

For example, the below image shows a picture of the lytic life cycle of the rabies virus, an enveloped animal virus.
external image

So in reality, a discussion of lytic and lysogenic lifestyles with respect to human viral infections IS in fact relevant.

Ecxellent post

We do have several anti-virals that are currently in use including:

Acyclovir
Amantadine
Cidofovir
Famciclovir
Foscarnet
Ganciclovir
Interferon Alfa-2b and Ribavirin
Oseltamivir
Penciclovir
Ribavirin
Rimantadine
Trifluridine
Valacyclovir
Valganciclovir
Vidarabine
Zanamivir

However, these agents can have some nasty side efects and many of them are only if truly needed

FredT,

Thanks for the info... I could look this up myself, but I figure if you've got the info, why bother. Are all of the drugs you posted unique? For example, are any of your examples duplicates... like a generic and a brand name? I wasn't aware that this many anti-virals available. Great info

No no duplicates. Some are not used very often.

Whats thay one (i think it starts with w), that hospitals use if they can't find the right drug to stop the infection from getting worse. (but only as a last resort as its quite dangerous if your healthy)?

Why are people so blind. We have may or may not have anti-viruses in a chemical form but we most certainly have a frequency cure which will kill almost any virus, pathogen etc. and eventually bring a balanced energy in ANY human, The money hungry businessman wants this information hidden from public view for reasons of profit margins, stocks and to pharm the cattle.

I dont think balancing energy will create cures for anything that will help everybody.

So you dismiss the fact about the technology and focus on the rhetorical point of the issue. Fool. So prove me wrong on a scientific level that this technology does not work.