HIV Infection

 

How Hiv attacks our bodies and how we can stop it:

 

The replication of hiv once it enters the body is a multi-staged process. Each step is crucial to successful replication, and therefore is a potential target for anti-retroviral drugs to stop the process. HIV is so dangerous to the body because it hides in the immune system itself, the system that is meant to attack its existence. This is what makes it so hard for white blood cells - the cells that fight viruses in the immune system - to find and destroy.

 

Step 1

The intial stage of the infection process involves the virus infecting a host cell in the immune system. HIV infects lymphocytes in the blood stream, which would otherwise act to eliminate the virus. These lymphocytes are called T cells, often referred to as CD4 cells. For HIV to enter the cell and multiply, there must be matching receptors and co receptors on the cell's surface. These receptors interact with protein complexes on the surface of the virus. The protein complexes on the virus are comprised of two glycol proteins. The first is an extra cellular protein and the second is a transmembrane protein. The extra cellular protein binds to the receptors and co receptors on the cell, changing the makeup of the extra cellular protein. This process, called attachment, allows the transmembrane protein to unfold from the virus and insert itself into the cell's membrane. The transmembrane, now attached to the virus and cell, folds back on itself to draw the virus towards the lymphocyte cell. This facilitates the virus membrane - it's outer layer - and the cell membrane to fuse together.

 

Step 2 

 

HIV enters the cell and brakes itself open. To replicate, the virus releases two viral RNA strands and three replication enzymes. The replication enzymes are intergrase, protease and reverse transcriptase. Reverse transcriptase is the first enzyme to do its job, it reverse transcribes the inscription of the two viral RNA, merging it with DNA from the host cell. Intergrase then creates two sticky ends of the newly formed DNA and transfers it into the nucleus of the cell, where it intergrates with the DNA of the nucleus. The cell know has the genetic information of HIV. This is why if a mother has a child, they will have HIV upon birth.

 

Step 3

 

RNA from the nucleus travels to the cell's cytoplasm, where the information is processed and simplifies by protease, the third and final replication enzyme. This step is crucial to create an infectious virus.

 

Step 4

 

Three replication enzymes and two RNA strands have been produced in this process, and come together to one again create the capsid of HIV, which leaves the host cell and acquires it's outer layer of protein complexes, allowing it to infect other cells in the immune system.

 

How we can stop it

 

HIV replicates billions of times per day, destroying the body's immune cells and its ability to fight disease, causing AIDS, or Auto Immune Deficiency Syndrome. To stop the infection of HIV before it fatally takes hold of the body, one of the key stages of HIV's replication needs to be interfered with. Anti-retroviral therapy can work by drugs inhibiting fusion of the cell and the virus or inhibition of reverse transcriptase by nucleoside inhibitors (RTIs). The action of intergrase can also be blocked, as well as protease from processing more HIV viruses. This is why research on antiretroviral drugs for HIV needs more support, as each step of its replication gives an opportunity for its prevention.