Quick facts

Did you know that there are two different types of HIV? HIV-1 is responisble for most of the HIV infections in the West, but in Africa both HIV-1 and HIV-2 can be found.

HIV-2 is know to be less aggressive than HIV-1, but after a period of years, produces the same clinical findings as HIV-1.

Ingestion
Harmful bacteria being ingested
by white blood cells.
Source: CLICK HERE

How it works

How HIV affects your body:

HIV works by attacking various parts of your body's immune system, particularly cells known as CD4 lymphocytes (these cells are the main fighting unit of our immune system). Although HIV does not directly make you sick, it eventually destroys your immune system's ability to defend your body. Thus, you have nothing to protect yourself from those everyday infections that you would normally be able to fight off.

Once the virus has reached this stage (when you are unable to fight off opportunistic infections), the person infected with HIV will have a CD4 count of less than 200 per millimetre cubed of blood, a very high Number of viruses found in your blood.viral load, and will be said to have Acquired Immune Deficiency Syndrome (AIDS).

Replication of the HI virus:

HIV
An animated image of the HI virus, this image
includes the viral RNA (thin wave-like yellow
structure in the centre of the nucleiod core
protein), the nucleoid core protein(rectangular
shapecovering the RNA), viral proteins and
enzymes (spheres in the core, on the RNA), the
matrix core protein (space between the
envelope and the nucleiod core protein), the
envelope and envelope proteins.
Source: CLICK HERE
  1. Once an HI virus has entered your body its first goal is to find a cell that it is capable of bonding with, and thus capable of infecting. The cell needs to have certain Molecule, group or site on a cell that can join with a specific molecule, antigen, hormone, or antibody.receptors on its surface. These receptors are found on only a few types of cells. Such as, white blood cells, brain cells, and intestinal cells.

  2. When the virus has fused with a cell, it penetrates the cell External wall of a cell.membrane and empties its contents (RNA, proteins and enzymes) into the host cell.

  3. Reverse Transcription now occurs. During this process, viral single stranded RNA is converted to double stranded pro-viral Substance that carries a cell's genetic information.DNA by the HIV reverse transcriptase enzyme.

  4. Integration occurs when pro-viral DNA is Joined with, merged with.incorporated into the DNA in the nucleus of the host cell by the integrase enzyme. The host cell becomes unable to Tell apart from.distinguish between its own DNA and the virus'.

  5. The host cell carries out the instructions programmed into the viral DNA; it makes copies of the viral Contains the genetic information for some viruses (HIV)RNA and proteins. This is the process of Transcription.

  6. During the next step the protease enzyme Joins, builds, brings together.cleaves the viral proteins into functional enzymes. The viral RNA and proteins now begin the formation of a new HI virus.

  7. Budding
    HIV budding from an
    infected cell
    Source: CLICK HERE
  8. The newly formed virus moves towards the surface of the host cell, in preparation for budding. When it is ready, the new HI virus buds off of the host cell using part of its External wall of a cellmembrane as its envelope.

  9. The new HI virus matures and now has the ability to infect other cells. It is now ready to begin this whole process all over again. Replication can directly kill the host cell, this is one of the ways in which HIV causes AIDS.

Animated replication of the HI virus

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Sources of information used in this page:

"Human Immunodeficiency Virus", Microsoft® Encarta® 2007 [CD]. Microsoft Corporation, 2006.
Bristol-Myers Squibb HIV & AIDS Brochure
http://www.youandaids.org/About%20HIVAIDS/Symptoms/index.asp
http://hivcare.blogspot.com/2007/06/life-cycle-of-hiv-virus-in-human-cell.html
Microsoft® Encarta® 2007. © 1993-2006 Microsoft Corporation. All rights reserved. (For Definitions)