View Full Version : AIDS, why so elusive???


sargentlard
12-02-03, 08:38 PM
Why is the AIDS virus so elusive? After all this extensive research done on the project why is the virus so tencious against being found a cure of? Surely they must have tried every angle so far to try to remedy the problem, yet no real success? Why?

Are they going about this the wrong way maybe? I am certainly no specialist in Biology but maybe the yneed to study what viruses truly are. How do the most basic ones work and why can we not eradicate them...even common ones such as the cold?

Its amazing that after, possibly, being the most studied virus there remains very little hope of getting rid of this menace......is its protein structure really that complex?

Idle Mind
12-03-03, 02:30 AM
It's not the complexity of viruses that's the issue. It's the simplicity. Since viruses are short strands of DNA or RNA, and are often single-stranded, they mutate incredibly quickly. And, since the genomes are small, there isn't a lot of unused DNA, which means there is a higher likelihood that they will be phenotypically changed by those mutations.

This allows them to modify their surface proteins used by the body to recognize particles.

They can last for a long time, since there is no metabolic activity, and no relpication when not in the cells. They do degrade, however, so they don't last forever.

Why is HIV so difficult to treat? I don't think they are so sure. It does have a long incubation period, so that may play a role. And, it destroys immune cells, which may be another factor(it is capable of destroying up to 50 at a time, by fusing cells into multi-nucleate masses called syncytia.)

There are people who are immune to the virus. The virus uses gp120 protein on its surface, which interacts with both the CD4 surface receptor, and the CCR5 protein as a co-receptor. It needs both before it can infect the cell. Some people in Europe have a mutated CCR5 that the virus cannot bind to, and therefore do not succumb to infection. They can still carry and spread the disease, but do not show symptoms.

As an aside, the gp120 protein is also why the virus can destroy multiple cells at once. It causes the host cell to express those proteins on their surface, which bind to the CD4 on other cells, and sticks a bunch of them together. The membranes fuse, causing multi-nuclear cells, which then lyse when they get too large.

spuriousmonkey
12-03-03, 04:59 AM
HIV is on of those extremely fast evolving viruses, compared for instance to HTLV. maybe that has something to do with it.

Craig Smith
12-03-03, 03:24 PM
HIV, HTLV are nothing compared with HDTV.

sargentlard
12-03-03, 07:42 PM
Originally posted by Idle Mind


They can last for a long time, since there is no metabolic activity, and no relpication when not in the cells. They do degrade, however, so they don't last forever.

How they do go on without any metabolic activity?

Why is HIV so difficult to treat? I don't think they are so sure. It does have a long incubation period, so that may play a role.

So if someone was found to have HIV at very early stages could they be in far less risk if treated?

Some people in Europe have a mutated CCR5 that the virus cannot bind to, and therefore do not succumb to infection. They can still carry and spread the disease, but do not show symptoms.

Do they suffer from the disease? Also are Hemopheliacs immune to it or am I thinking of Malaria?


HIV is on of those extremely fast evolving viruses, compared for instance to HTLV. Maybe that has something to do with it.

Have they tried to attack it from that angle then...to destroy its DNA?

Idle Mind
12-03-03, 09:24 PM
How they do go on without any metabolic activity?Viruses don't metabolize because they replicate inside the host cell. They commandeer the cell's energy when inside the cell during replication, but do not metabolize outside the cell.So if someone was found to have HIV at very early stages could they be in far less risk if treated?The thing about this is, HIV is very difficult to diagnose, because there are no symptoms. However, the virus would indeed be easier to treat at this stage.Do they suffer from the disease? Also are Hemopheliacs immune to it or am I thinking of Malaria?No. Since infection cannot take place, the virus can't enter the cell, and they don't develop symptoms. People are immune to malaria, or at least more resistant to, when they have sickle-cell anemia. Not exactly the most pleasant means of resistance, but it works.Have they tried to attack it from that angle then...to destroy its DNA?Yes. But, in order to get to the viral DNA, you have to target the viral particles. This is basically what the immune system does. However, the hurdles are there.

skyederman
12-03-03, 11:52 PM
There are vaccines in development but HIV does mutate quickly so they won't be as effective as for some other viruses.

For antiviral drugs the problem is that the chances of the drug meeting up with the viral protein it is designed to attack aren't always good enough to halt the worsening of the disease. Often it is though, and drugs treatments dramatically increase life expectancy, but then not everyone with the disease has access to the drugs.

There are things which break up DNA but they would also break up our DNA, so the side effects would be pretty nasty.

spuriousmonkey
12-04-03, 03:10 AM
one possible treatment is strangely enough to treat the HIV with mutagens. The rate of evolution of HIV is on the border of what is endurable to a virus. Pushing the evolution rate it a little bit further will actually diminish the fitness of the virus.

Idle Mind
12-04-03, 05:36 AM
Spurious, I am sure I am missing something, but how can you target the DNA of the HIV particles specifically?

spuriousmonkey
12-15-03, 06:33 AM
you can use mutagenic substances that accelerate the mutation rate. I have seen some graphs during a lecture, but can't remember what, which and how exactly.

ElectricFetus
12-15-03, 10:26 AM
HIV mutates so quickly that a cure is very difficult to generate. That like asking why we don’t have a cure for influenza and the common cold! There is some hope in using RNA interference and genetic engineering immune cell cultures to be resistant to the virus through lack of the appropriated receptors.

Ice
12-15-03, 06:08 PM
http://www.niaid.nih.gov/daids/therapeutics/research/2002HIV_RA_sumPath.htm

Check out the third point in this link! Its talking about the potential use of siRNA (small interfering mRNA) in AIDS treatment! I think it seems like a good method of AIDS control, because it is specific, and hopefully wont cause any negative effects to eukaryotic cells!!

Idle Mind
12-15-03, 11:20 PM
Spurious, I guess my question then becomes this: Are there sequence specific mutagens? How do you ensure that you don't develop other problems from having your own DNA mutated along with the virus'?

spuriousmonkey
12-16-03, 08:45 AM
i think that there are mutagens to which some viruses are more susceptible than others.

sargentlard
12-19-03, 05:12 PM
Is the DNA sequence of the AIDS virus known?

ElectricFetus
12-19-03, 05:53 PM
Yes the genome of HIV is know. Aaaaaah I hate to tell you this people but HIV has no DNA: its a retrovirus it only has single stranded RNA and a reverse transcriptase… and yes most HIV drugs attack that transcriptase, the virus just evolves a mutated transcriptase that will not bind to the drug.

Idle Mind
12-20-03, 02:59 AM
I know that WellCooked, but a lot of mutagenic substances are for nucleic acids in general, so they would still work.

ElectricFetus
12-20-03, 03:20 AM
yes but what’s going to prevent it from damaging cellular DNA?

spuriousmonkey
12-20-03, 03:33 AM
Would you rather not have aids and an increased chance for cancer, or have Aids and no increased chance for cancer?

ElectricFetus
12-20-03, 04:28 AM
I just don't see the logic in it, we design drugs to attack the differences in a pathogen from its host, like drugs against reverse transcriptase.

spuriousmonkey
12-20-03, 05:20 AM
this approach is not influenced by the evolution of the virus, since it uses the evolution of the virus as a weapon. Hence no resistance.

does it make sense now?

ElectricFetus
12-20-03, 05:44 AM
No it still does not, the side effects would be horrible. There is a good likely hood that the treatment is going to kill the person instead of the disease. You have to demonstrate that the virus is affected far more by your mutagen then the patient before your treatment can be considered viable.

spuriousmonkey
12-20-03, 06:01 AM
You assume the side effects are horrible. There might be (and probably are) drugs that affect the polymerase of retro viruses specifically.

Nobody suggested to use a mutagen that works equally well for cellular life and viral life.

ElectricFetus
12-20-03, 08:19 AM
You assume the side effects are horrible. There might be (and probably are) drugs that affect the polymerase of retro viruses specifically.
http://www.crazybarki.messageboard.nl/forum/images/smiles/shout2.gif HELLO! that’s what most AIDS treatment drugs attack already, the reverse transcriptase. Sense humans and in fact almost all life does not have or use reverse transcriptase the drug has no direct side effects.

spuriousmonkey
12-21-03, 07:53 AM
Hello, this treatment would work for any fast evolving virus!

And why isn't aids cured if your drug is so effective?

and this isn't about who has the biggest penis, this is about interesting approaches.

Only in america the best count, in the rest of the world depth counts.

ElectricFetus
12-21-03, 02:44 PM
Because the virus adapts modifications to the trancriptase that makes the drug less of a ligant. tell me how are you going to make it so that your drug effects the virus rather then the person and then how are you going to counter new strains that have developed resistance to your drug?

spuriousmonkey
12-29-03, 08:32 AM
you don't seem to realize that there is no problem of resistance. You make them evolve faster, you don't try to kill them, but the side effect of faster evolution is that they go extinct.

sargentlard
12-29-03, 08:41 AM
Originally posted by spuriousmonkey
but the side effect of faster evolution is that they go extinct.

Really? Interesting, i have never heard that before. Does that apply to every species.

spuriousmonkey
12-29-03, 08:56 AM
well, the thing is that AIDS is a relaive 'new' virus (in the human species) and typical of these kind of retroviruses that just jumped to a different host is that they cause more severe effects than in the original host and that they tend to evolve faster. AIDS is one of those viruses which evolutionary speed is on the border of what is survivable. Hence the theory that if you push them slightly over this border the system of 'quasi species going through succesive bottlenecks' loose too much fitness and go extinct.

coluber
01-19-04, 06:25 PM
what about people born without t reseptors? :bugeye:

spuriousmonkey
01-20-04, 04:50 AM
what about people born without t reseptors? :bugeye:

That might be semi-lethal or cause of auto-immune diseases????????

ElectricFetus
01-20-04, 12:18 PM
I think he means the CCR4 receptor.

coluber
01-21-04, 11:15 AM
yes sorry i didn't remember what it was called just the shape :o

ElectricFetus
01-21-04, 12:52 PM
coluber,

here then check out these sites:
http://www.aegis.com/pubs/aidswkly/1997/AW971201.html
http://www.aidsmeds.com/news/20020716epid001.html
http://www.aegis.com/news/newsday/2000/ND000201.html

Idle Mind
01-21-04, 01:22 PM
Ahem, CCR5. CD4 is the main receptor that the HIV gp120 binds to, and CCR5 is the co-receptor. A minor unimportant detail, and it's easy to get mixed up. Ignore this post at will.

ElectricFetus
01-21-04, 01:27 PM
yes its was a mix up so sorry. :)

Fuck you!