HIV

Hello readers! Today, I was reading an intriguing article about a radical treatment in HIV gene therapy, replacing immune cells with genetically modified versions, using GM cells which has been hailed a success after its trial. Great news all around! It certainly poses as a possible alternative treatment method, as it has been declared by scientists as a success after the first clinical trial. The tests on people enrolled in the trial found that the disease-resistant cells (the GM versions) multiplied in their bodies. The trial poses as a potential new therapy for HI; as a few shots of the modified immune cells can become an alternative for HIV patients who currently spend the rest of their lives on antiretroviral drugs - issues of which can results in side effects, people missing days and drug-resistance. From this, I'll move my post into its topic of the day, HIV, where I will be outlining what it is and how it occurs.

HIV
What is it?
It stands for human immunodeficiency virus. The virus attacks the immune system, which in turn weakens your ability to fight infections and disease. AIDS is the final stage of HIV infection, which the stage where your body can no longer fight life-threatening infections. However, with early diagnosis and treatment, most people will HIV will not reach this stage. However, without treatment, a person with HIV's immune system will become seriously damaged, and will develop life-threatening illnesses such as cancer.
It was first discovered in 1981 in a remote area of central Africa, and since then, swept across the globe, infecting millions in a relatively short period of time. AIDS has killed more than 28 million people, with up to 3.6 million people dying in 2005 alone.  

How does it occur?
HIV is spread most commonly by having sex with someone who has HIV without a condom. However, it can also be passed on by oral sex, sharing sex toys, sharing infected needles and other injecting equipment and from an HIV-positive mother to her child during pregnancy, birth and breastfeeding. This is because HIV is found in the body fluids of an infected person; which includes semen, vaginal and anal fluids, blood and breast milk. It is a fragile virus so cannot live very long outside the body and cannot be transmitted through sweat or urine. Ninety-five percent of those diagnosed with HIV in the UK has acquired HIV as a result of sexual contact.
One of the big issues with HIV is that a person can carry and transmit the HIV virus for many years before any symptoms show themselves. So a person can be contagious for a decade or even longer before any signs of disease become apparent. The issue at hand is, for example, for ten years, a promiscuous HIV carrier can potentially infect dozens of people, who can then in turn each infect dozens of people, and so on. 

What happens?
HIV invades the cells of our immune systems, and reprograms the cells to become HIV-producing factories. The number of immune cells in the body begins to dwindle and then AIDS develops. Once it manifests, a person is susceptible to many infections, and due to the weak immune system, it cannot fight back effectively. HIV has also been shown to be able to mutate, which makes treating the virus nearly impossible. HIV is therefore a disease which both invades and destroys the immune system which normally can protect the body from a virus. It paradoxically corrupts and disables a system that should be guarding against HIV, making it both a prevalent and successful disease. 
Like all viruses, HIV requires a host cell to stay alive and replicate. In order to do so, the virus creates new virus particles inside a host cell, and those fragile particles carry the virus to new cells. Made up of genetic instructions wrapped inside a protective shell, an HIV virus particle, called a virion, is a spherical cell. It infects something called the T-helper cells (one of the cells that works in the immune system) and once infected, the T-helper cells turns into an HIV-replicating cell. HIV will slowly reduce the number of T-cells until the person develops AIDS.
HIV is a retrovirus; it has genes composed of ribonucleic acid (RNA). Like all viruses, HIV, when replicating inside host cells, is considered a retrovirus because it used an enzyme, called reverse transcriptase, which converts RNA into DNA. 
The HIV virus, once it enters the body and heads for the T-helper cells it:

• Binds to the immune cell, where a protein of the HIV virus binds with a protein of the T-helper cell. The viral core enters the T-helper cell and the virion's protein membrane fuses with the cell membrane
• Reverse transcription then occurs - the viral enzyme, reverse transcriptase, copies the virus's RNA into DNA
• Integration - the newly created DNA is then carried into the cell's nucleus by an enzyme called viral integrase which then binds with the cell's DNA. HIV DNA is called a provirus
• The transcription occurs where the viral DNA in the nucleus seperates and creates messenger RNA (mRNA), which uses the cell's own enzymes. The mRNA contains the instructions for making new viral proteins.
• Translation - the mRNA is then carried back out of the nucleus by the cell's enzymes, and the virus uses the cell's natural protein-making mechanisms to create long chains of viral proteins and enzymes
• Assembly - RNA and viral enzymes then gather at the edge of the cell while an enzyme called protease cuts the polypetides (the chains of proteins) into viral proteins
• Budding - the new HIV virus particles come out from the cell membrane and break away with a piece of the cell membrane surrounding them. And so this is how the enveloped viruses leave the cell. This way, the host cell is not destroyed.

The virions will infect other T-cells and causes the person's T-helped cell count to fall. The lack of them compromises the immune system, and after a certain number of them fall, the person infected is considered to have AIDS. An AIDS-infected person dies from infections as a result because their immune system has been dissipated. An AIDS patient could die from the common cold as easily as he or she could from cancer because the person's body cannot fight off the infection. 

What treatments are currently available?
There is currently no cure for HIV, however there is a lot of treatments at hand which can enable a person living with HIV to live a long life, without HIV developing into AIDs. There is an emergency anti-HIV medication called PEP (post-exposure prophylaxis) which may stop you from becoming infected, but treatment must be started within three days of coming into contact with the virus. This is a treatment that would work well especially with HIV-positive mothers giving birth, as a prevention technique to stop their child from contracting HIV. Medication, known as antiretrovirals, works by slowing down the damage the virus does to the immune system, which come in the form of tablets that must be taken every day. Someone with HIV will be encouraged to take regular exercise, eat healthily, stop smoking, have yearly flu jabs and pneumococcal vaccinations to minimize the risk of getting serious illnesses.

Thanks for reading