How To STOP an HIV Infection in it's Tracks
In the previous Blog, I cited some now old evidence that caffeine and theophylline, both methylxanthine drugs, can prevent ALREADY INFECTED T cells from producing more virus.
Now for something completely different.
Background.
When the HIV or other retroviruses enter cells, their RNA is turned into DNA by a viral enzyme called reverse transcriptase. This DNA complexes with proteins and enters the nucleus of the cell. In the nucleus, the viral protein integrase "cuts and pastes" the viral DNA into the DNA of the cell. This complex is initially very unstable. Normal cellular proteins "fill in the gaps" and the DNA integration becomes stable, capable of producing virus.
Here is the fascinating part of the story. If the normal cellular proteins cannot fill in the gaps, a stress response is initiated which results in the death of the cell. Cells cannot replicate properly if their DNA is damaged. This is the entire point behind the use of radiation and genotoxic chemo drugs in cancer therapies.
Many biotech and Big Pharma companies have invested hundreds of millions of dollar on drugs that block viral protease, reverse transcriptase and integrase activities. As we will now see, this money has been largely wasted. There is a better way to control HIV infections.
The following article shows that phosphatidylinositol 3-kinase inhibitors such as LY294002 (quercetin) suppresses virus infection in EITHER CD4 T cells or macrophages. Further, this inhibitor affects the expression of BOTH CXCR4 and CCR5 specific HIV viruses.
This is the interesting part. LY294002 does not prevent viral entry into the cells, and it does not block reverse transcriptase activity. Once the viral gene becomes integrated into the cellular DNA, this drug has NO affect on HIV synthesis.
This means that LY294002 is probably interfering with viral integrase activity. But how?
http://www.ncbi.nlm.nih.gov/entrez/queryd.fcgi?cmd=Retrieve&db=pubmed&
dopt=Abstract&list_uids=12551992&itool=pubmed_docsum
LY294002 is a form of quercetin that has been modified to selectively inhibit PI-3K kinase activity. There is more than one PI-3K enzyme. In addition to membrane associated PI-3K that activates AKT, mTOR is also a member of the PI-3K family of enzymes as is a very important DNA repair enzyme, to be discussed later. There is NO evidence that LY294002, a specific inhibitor of PI-3K enzymes, can inhibit any HIV processing proteins such as HIV integrase.
We have two issues to discuss and they are both equally exciting.
First, the flavonoid quercetin, not its derivative LY294002, is a POTENT HIV integrase inhibitor. Quercetin inhibits both functions of the integrase enzyme at concentrations that are attainable in the body...with a little work.
http://www.ncbi.nlm.nih.gov/entrez/queryd.fcgi?cmd=Retrieve&db=pubmed&
dopt=Abstract&list_uids=8460151&itool=pubmed_docsum
Let me make this very clear. If the viral integrase enzyme is inhibited by quercetin, an HIV infection must cease to exist. It will "burn out", pure and simple. The virus DNA MUST integrate into the cellular DNA in order to produce virus. Of course, this has nothing to do with cells that are already infected with the HIV virus. However, these cells will die eventually. All viral infections DEPEND on the infection of new cells in order to produce more virus. If the data cited above is correct, this will NOT happen in the presence of sufficient concentrations of quercetin.
So it is very good news that quercetin can directly bind and inhibit the HIV integrase enzyme.
But this doesn't really explain the first scientific paper on the role LY294002 plays in blocking the replication of the HIV virus in both CD4 T cells and macrophages. Quercetin can probably inhibit ANY enzyme that LY294002 can, but the reverse is NOT true. LY294002 is a highly specific inhibitor of only PI-3K type kinases. HIV integrase does not fall into this category. So what is LY294002 doing to inhibit HIV synthesis?
This is our second issue, and it's something, one week ago, I knew nothing about.
Background.
Viral integrase proceeds in two steps to partially integrate viral DNA into the DNA of the cell. Cellular kinase enzymes MUST complete the process or the cells will die from apoptosis or programmed cell death.
The host protein DNA-PK completes the process of viral DNA integration into cellular DNA. This enzyme is critical for retroviral DNA integration.
http://www.ncbi.nlm.nih.gov/entrez/queryd.fcgi?cmd=Retrieve&db=pubmed&
dopt=Abstract&list_uids=10213687&itool=pubmed_docsum
If this process is blocked, the viral integrase process will initiate an ATR-dependent DNA damage response. In simple English, this means if viral integrase "cuts" cellular DNA in an effort to integrate viral DNA, and if this cellular damage is not repaired rapidly by DNA-PK, the cell initiates a DNA damage response. This response can stimulate the activity/synthesis of enzymes that repair the DNA damage caused by HIV integrase.
http://www.ncbi.nlm.nih.gov/entrez/queryd.fcgi?cmd=Retrieve&db=pubmed&
dopt=Abstract&list_uids=12679521&itool=pubmed_docsum
What does this mean?
Simply put, it would be nice to inactive the viral integrase enzyme directly, and to inhibit BOTH the DNA-PK and ATR DNA repair enzymes. And this is why...
Wortmannin is a VERY specific inhibitor of PI-3K enzymes. This includes membrane associated PI-3K, mTOR and the DNA-PK enzyme, which is also a PI-3K enzyme. Wortmannin is at least 50-100 times more potent than LY294002 in inhibiting PI-3K enzymes. It is terribly toxic to mice, negating its use as a clinical drug.
The drug wortmannin enhances the ability of viral integrase to kill lymphocytes by directly inhibiting the activity of DNA-PK, a member of the PI-3K enzyme family. If DNA-PK is inhibited, the viral integrase process cannot proceed to completion, resulting in cellular DNA damage. If this damage is not repaired, the cell dies.
http://www.ncbi.nlm.nih.gov/entrez/queryd.fcgi?cmd=Retrieve&db=pubmed&
dopt=Abstract&list_uids=11158303&itool=pubmed_docsum
Wortmannin's ability to block DNA repair results in the death of both radiation treated cells and those newly infected with HIV virus.
http://www.ncbi.nlm.nih.gov/entrez/queryd.fcgi?cmd=Retrieve&db=pubmed&
dopt=Abstract&list_uids=13678345&itool=pubmed_docsum
What is ATR and how can it prevent integrase induced DNA damage?
In the previous Blog, I showed that methylxanthine drugs such as caffeine and theophylline can block the ATM enzyme. This means that cells cannot "pause" at the G2 phase of the cell cycle, thereby producing more virus.
Caffeine and theophylline can also inhibit the ATR enzyme, resulting in an inhibiton of DNA repair. If you block DNA-PK activity with PI-3K inhibitors, you STILL need to block ATR activity.
Confused? Read on.
Overview
1. Quercetin itself can potently block HIV integrase activity. This is a direct affect on the integrase enzyme activity which does NOT result in the death of newly infected cells. It simply prevents them from being infected.
2. Inhibitors of PI-3K enzymes, such as quercetin, LY294002, and wortmannin, can block viral infection of new cells by blocking DNA-PK activity. This results in a defective integration of viral DNA into cellular DNA, and cell death. Worthmannin has been identified as a DNA-PK inhibitor in MANY studies. Quercetin and LY294002 have not been directly identified as DNA-PK inhibitors, but this can be implied by the data. DNA-PK IS a PI-3K kinase therefore it should be inhibited by quercetin and LY294002.
3. Inhibiting DNA-PK promotes cellular death in normal cells that have been infected with as few as two viral particles.
http://www.ncbi.nlm.nih.gov/entrez/queryd.fcgi?cmd=Retrieve&db=pubmed&
dopt=Abstract&list_uids=11238839&itool=pubmed_docsum
4. Inhibiting DNA-PK causes normal cells, recently infected with as few as two viral particles, to die. This means these cells cannot become reservoirs for viral synthesis.
5. Inhibiting DNA-PK with PI-3K enzyme inhibitors is not enough to prevent stable HIV infection in newly infected T cells and macrophages. The DNA damage stress enzyme ATR must also be inhibited. Otherwise, the damage done by the viral integrase enzyme, in the presence of DNA-PK inhibitors, can be repaired.
6. Caffeine and theophylline can both inhibit the ATR enzyme. The effective concentration of caffeine is 4 mM, which is almost 4 grams in a human per day. This is way too much caffeine. Theophylline is more effective at lower concentrations, but it is a prescription drug.
Retrospect.
You CAN block HIV infection of new cells using natural medicines by a variety of different pathways. Viral integrase activity can either be directly inactivated by quercetin, or quercetin-like natural medicines, PI-3K enzyme inhibitors, can cause newly infected cells to die because the integration process is blocked, resulting in cellular death.
In the presence of quercetin, a natural flavonoid found in many fruits and vegetables, HIV infections can indeed be stopped in their tracks.
Stay tuned...the rain has stopped today and the sun is shinning. A good sign.
Grouppe Kurosawa, Medicine in the Public Interest
(http://www.grouppekurosawa.com)
Now for something completely different.
Background.
When the HIV or other retroviruses enter cells, their RNA is turned into DNA by a viral enzyme called reverse transcriptase. This DNA complexes with proteins and enters the nucleus of the cell. In the nucleus, the viral protein integrase "cuts and pastes" the viral DNA into the DNA of the cell. This complex is initially very unstable. Normal cellular proteins "fill in the gaps" and the DNA integration becomes stable, capable of producing virus.
Here is the fascinating part of the story. If the normal cellular proteins cannot fill in the gaps, a stress response is initiated which results in the death of the cell. Cells cannot replicate properly if their DNA is damaged. This is the entire point behind the use of radiation and genotoxic chemo drugs in cancer therapies.
Many biotech and Big Pharma companies have invested hundreds of millions of dollar on drugs that block viral protease, reverse transcriptase and integrase activities. As we will now see, this money has been largely wasted. There is a better way to control HIV infections.
The following article shows that phosphatidylinositol 3-kinase inhibitors such as LY294002 (quercetin) suppresses virus infection in EITHER CD4 T cells or macrophages. Further, this inhibitor affects the expression of BOTH CXCR4 and CCR5 specific HIV viruses.
This is the interesting part. LY294002 does not prevent viral entry into the cells, and it does not block reverse transcriptase activity. Once the viral gene becomes integrated into the cellular DNA, this drug has NO affect on HIV synthesis.
This means that LY294002 is probably interfering with viral integrase activity. But how?
http://www.ncbi.nlm.nih.gov/entrez/queryd.fcgi?cmd=Retrieve&db=pubmed&
dopt=Abstract&list_uids=12551992&itool=pubmed_docsum
LY294002 is a form of quercetin that has been modified to selectively inhibit PI-3K kinase activity. There is more than one PI-3K enzyme. In addition to membrane associated PI-3K that activates AKT, mTOR is also a member of the PI-3K family of enzymes as is a very important DNA repair enzyme, to be discussed later. There is NO evidence that LY294002, a specific inhibitor of PI-3K enzymes, can inhibit any HIV processing proteins such as HIV integrase.
We have two issues to discuss and they are both equally exciting.
First, the flavonoid quercetin, not its derivative LY294002, is a POTENT HIV integrase inhibitor. Quercetin inhibits both functions of the integrase enzyme at concentrations that are attainable in the body...with a little work.
http://www.ncbi.nlm.nih.gov/entrez/queryd.fcgi?cmd=Retrieve&db=pubmed&
dopt=Abstract&list_uids=8460151&itool=pubmed_docsum
Let me make this very clear. If the viral integrase enzyme is inhibited by quercetin, an HIV infection must cease to exist. It will "burn out", pure and simple. The virus DNA MUST integrate into the cellular DNA in order to produce virus. Of course, this has nothing to do with cells that are already infected with the HIV virus. However, these cells will die eventually. All viral infections DEPEND on the infection of new cells in order to produce more virus. If the data cited above is correct, this will NOT happen in the presence of sufficient concentrations of quercetin.
So it is very good news that quercetin can directly bind and inhibit the HIV integrase enzyme.
But this doesn't really explain the first scientific paper on the role LY294002 plays in blocking the replication of the HIV virus in both CD4 T cells and macrophages. Quercetin can probably inhibit ANY enzyme that LY294002 can, but the reverse is NOT true. LY294002 is a highly specific inhibitor of only PI-3K type kinases. HIV integrase does not fall into this category. So what is LY294002 doing to inhibit HIV synthesis?
This is our second issue, and it's something, one week ago, I knew nothing about.
Background.
Viral integrase proceeds in two steps to partially integrate viral DNA into the DNA of the cell. Cellular kinase enzymes MUST complete the process or the cells will die from apoptosis or programmed cell death.
The host protein DNA-PK completes the process of viral DNA integration into cellular DNA. This enzyme is critical for retroviral DNA integration.
http://www.ncbi.nlm.nih.gov/entrez/queryd.fcgi?cmd=Retrieve&db=pubmed&
dopt=Abstract&list_uids=10213687&itool=pubmed_docsum
If this process is blocked, the viral integrase process will initiate an ATR-dependent DNA damage response. In simple English, this means if viral integrase "cuts" cellular DNA in an effort to integrate viral DNA, and if this cellular damage is not repaired rapidly by DNA-PK, the cell initiates a DNA damage response. This response can stimulate the activity/synthesis of enzymes that repair the DNA damage caused by HIV integrase.
http://www.ncbi.nlm.nih.gov/entrez/queryd.fcgi?cmd=Retrieve&db=pubmed&
dopt=Abstract&list_uids=12679521&itool=pubmed_docsum
What does this mean?
Simply put, it would be nice to inactive the viral integrase enzyme directly, and to inhibit BOTH the DNA-PK and ATR DNA repair enzymes. And this is why...
Wortmannin is a VERY specific inhibitor of PI-3K enzymes. This includes membrane associated PI-3K, mTOR and the DNA-PK enzyme, which is also a PI-3K enzyme. Wortmannin is at least 50-100 times more potent than LY294002 in inhibiting PI-3K enzymes. It is terribly toxic to mice, negating its use as a clinical drug.
The drug wortmannin enhances the ability of viral integrase to kill lymphocytes by directly inhibiting the activity of DNA-PK, a member of the PI-3K enzyme family. If DNA-PK is inhibited, the viral integrase process cannot proceed to completion, resulting in cellular DNA damage. If this damage is not repaired, the cell dies.
http://www.ncbi.nlm.nih.gov/entrez/queryd.fcgi?cmd=Retrieve&db=pubmed&
dopt=Abstract&list_uids=11158303&itool=pubmed_docsum
Wortmannin's ability to block DNA repair results in the death of both radiation treated cells and those newly infected with HIV virus.
http://www.ncbi.nlm.nih.gov/entrez/queryd.fcgi?cmd=Retrieve&db=pubmed&
dopt=Abstract&list_uids=13678345&itool=pubmed_docsum
What is ATR and how can it prevent integrase induced DNA damage?
In the previous Blog, I showed that methylxanthine drugs such as caffeine and theophylline can block the ATM enzyme. This means that cells cannot "pause" at the G2 phase of the cell cycle, thereby producing more virus.
Caffeine and theophylline can also inhibit the ATR enzyme, resulting in an inhibiton of DNA repair. If you block DNA-PK activity with PI-3K inhibitors, you STILL need to block ATR activity.
Confused? Read on.
Overview
1. Quercetin itself can potently block HIV integrase activity. This is a direct affect on the integrase enzyme activity which does NOT result in the death of newly infected cells. It simply prevents them from being infected.
2. Inhibitors of PI-3K enzymes, such as quercetin, LY294002, and wortmannin, can block viral infection of new cells by blocking DNA-PK activity. This results in a defective integration of viral DNA into cellular DNA, and cell death. Worthmannin has been identified as a DNA-PK inhibitor in MANY studies. Quercetin and LY294002 have not been directly identified as DNA-PK inhibitors, but this can be implied by the data. DNA-PK IS a PI-3K kinase therefore it should be inhibited by quercetin and LY294002.
3. Inhibiting DNA-PK promotes cellular death in normal cells that have been infected with as few as two viral particles.
http://www.ncbi.nlm.nih.gov/entrez/queryd.fcgi?cmd=Retrieve&db=pubmed&
dopt=Abstract&list_uids=11238839&itool=pubmed_docsum
4. Inhibiting DNA-PK causes normal cells, recently infected with as few as two viral particles, to die. This means these cells cannot become reservoirs for viral synthesis.
5. Inhibiting DNA-PK with PI-3K enzyme inhibitors is not enough to prevent stable HIV infection in newly infected T cells and macrophages. The DNA damage stress enzyme ATR must also be inhibited. Otherwise, the damage done by the viral integrase enzyme, in the presence of DNA-PK inhibitors, can be repaired.
6. Caffeine and theophylline can both inhibit the ATR enzyme. The effective concentration of caffeine is 4 mM, which is almost 4 grams in a human per day. This is way too much caffeine. Theophylline is more effective at lower concentrations, but it is a prescription drug.
Retrospect.
You CAN block HIV infection of new cells using natural medicines by a variety of different pathways. Viral integrase activity can either be directly inactivated by quercetin, or quercetin-like natural medicines, PI-3K enzyme inhibitors, can cause newly infected cells to die because the integration process is blocked, resulting in cellular death.
In the presence of quercetin, a natural flavonoid found in many fruits and vegetables, HIV infections can indeed be stopped in their tracks.
Stay tuned...the rain has stopped today and the sun is shinning. A good sign.
Grouppe Kurosawa, Medicine in the Public Interest
(http://www.grouppekurosawa.com)
0 Comments:
Post a Comment
<< Home