This lesson will delve into the basics of HIV therapy. You will learn about cocktails, protease inhibitors and reverse transcriptase inhibitors, as well as how they work and how they are used.
Life Expectancy with HIV
One of the world’s most well known viruses, HIV, has also some of the most interesting treatments. There is no cure or vaccine for HIV. However, all else equal, early intervention and a proper treatment plan may help a person live a life almost as long as they would have lived if they never got infected with HIV in the first place.On the flipside, if a person is left untreated, they may develop a late stage HIV condition known as AIDS in less than five years post infection. Once AIDS occurs, there may be less than one year left to live without proper treatment.
Reverse Transcriptase ; Protease Inhibitors
HIV is a virus that has, among many others, two key components that help it replicate and mature.
These are enzymes called reverse transcriptase and HIV protease. Again, these two enzymes should not be found in healthy human cells, since they are involved in helping HIV (not our body’s cells) replicate and mature.This is precisely why reverse transcriptase inhibitors are used to fight an HIV infection. These are antiviral drugs that stop HIV from copying and therefore inserting its genome into a healthy cell. Since these drugs do not allow the RNA viral genome to be converted into DNA by viral reverse transcriptase, the virus cannot insert a DNA copy of its genome into the host cell, which means it cannot replicate or reproduce itself.
These reverse transcriptase inhibitors are often used in conjunction with HIV protease inhibitors, which are drugs that prevent HIV from making functional enzymes and structural proteins. When HIV replicates itself, it needs to generate structural proteins and enzymes, such as reverse transcriptase, both of which will then be used by the baby virus to infect another cell.Well, when these proteins and enzymes are first made, they are immature. They need to be polished off, so to speak. Therefore, unless these immature proteins are properly clipped and cleaned by the HIV protease, they cannot function, which means the HIV babies are dead in the water, so to speak.
Unfortunately, HIV is a tricky little thing. When it infects and replicates within a cell, it must copy its genome. However, HIV is like a really drunk writer.
When copying a manuscript (its genome), this writer cannot copy every letter correctly. The end result is a manuscript that is ever so slightly different than the original. The manuscript’s understandable output, the words we can read or the proteins used by HIV to replicate and infect, are what is targeted by antiretroviral therapy. This is a combination of drugs known as a cocktail that is used to try and control HIV.
The problem is that when an antiviral drug comes across an unrecognizable word (the protein), it doesn’t know how to interpret it. If it can’t interpret it, then it cannot do anything about it. If it cannot do anything about it, then it cannot stop HIV from replicating, maturing and becoming infective.This is precisely why a cocktail of drugs is used to try and control HIV. The term cocktail implies that more than one drug, each one targeting a slightly different part of HIV, is used to try and prevent it from functioning properly. That is to say, if one drug cannot understand the weird new word written out by the drunken writer, then hopefully another drug will be able to understand that word or enough of the other words in order to enable it to control the HIV through different means.
That’s basically saying that if a protease inhibitor fails to work because of an HIV mutation, then a reverse transcriptase inhibitor in the cocktail will still be able to do its job, because the mutation wasn’t large enough to affect all the targets of antiretroviral therapy.
As you can tell, keeping HIV at bay is a daunting task, and resistance to a certain drug is not uncommon. Therefore, antiretroviral therapy, which is a combination of drugs known as a cocktail that is used to try and control HIV, is utterly necessary. This cocktail often includes reverse transcriptase inhibitors, which are antiviral drugs that stop HIV from copying and therefore inserting its genome into a healthy cell, and HIV protease inhibitors, which are drugs that prevent HIV from making functional enzymes and structural proteins.
At the end of this lesson, you’ll be able to:
- Explain why a combination of drugs is necessary to treat HIV
- Describe the functions of reverse transcriptase inhibitors and HIV protease inhibitors