Friday, 15 April 2011

Infected by HIV - My understanding@Phil and Peter

HIV (Human Immunodeficiency Virus) can be contracted in three ways:

  • Infected blood passing through the skin barrier, possibly via a deep graze, needle puncture, a cut or a wound.
  • In the womb or at birth, when a mother who is HIV-positive or who has AIDS (Acquired Immune Deficiency Syndrome) passes the infection to her baby. This may take place across the placenta during pregnancy, or during childbirth itself. An HIV-positive mother can also transmit the virus to her baby via breastfeeding.
  • Having unsafe sex. (as opposed to 'safer' sex. The term 'safe sex' is no longer used). This is the most common way to contract HIV whether a person is male, female, heterosexual or homosexual. Safer sex is defined by any sexual practice which does not allow the partner's blood or semen inside the body - HIV counsellors say the rule is 'on, not in'.

These pictures are from Dr. Klappa's lecture and are simple diagrams of the HIV cell itself.

Question @PETER - Does the HIV cell 'mature' when it has infected the cell?

HIV Infection process

I will research deeper into this process, as I understand it at the moment, HIV infects cells in the immune and central nervous system's. One of the main cells it infects is the 'T helper lymphocyte', a cell that coordinates the actions of other immune system cells. Question @Peter - are 'T helpers' white blood cells and do you want the animation to be a process of one of these being infected?

I believe the above image is a diagram of a 'T helper' being infected because the cell membrane has CD4 receptor's on it's membrane. HIV attaches to the CD4 receptor and gains entry. Question @Peter - does the HIV cell actually penetrate the cell membrane? I seem to remember you saying that it doesn't but I maybe mistaken?

A healthy cell reproduces itself in it's cell nucleus, which contains the DNA (double stranded 4 bases A, C, T, G). Through a process called 'transcription' the DNA is broken down into RNA (single stranded 4 bases A, C, U, G). RNA is then broken down through a process called 'translation' into protein called amino acids (the basic building blocks of life).

HIV uses 'reverse transcription', synthesizing RNA into viral DNA. Viral DNA then integrates into the cell genome in the nucleus. The cell begins the cycle (viral transcription & translation); virus DNA creates virus RNA creates virus PROTEIN. The resulting amino acids (protein) reconstructs new HIV cells. These new cells go onto infect other cells and the process is repeated.

HIV infection eventually leads to a severe reduction in 'T helper' cells available to help fight disease. A CD4 test (or CD4 count) is used to measure the number of T helper's in the carriers blood. When the count decreases to a critical level, the individual is said to have progressed to AIDS (Acquired Immune Deficiency Syndrome) and is susceptible to infections and cancers.

The process of HIV infection can be broken down into four stages:
  • Stage 1: Primary HIV infection - the subject of my animation detailed above. During this stage the body releases HIV antibodies.
  • Stage 2: Clinically asymptomatic stage - usually between 5 - 10 years, free of symptoms but HIV is not dormant.
  • Stage 3: Symptomatic stage - carrier's shows symptoms as theimmune system is severely damaged and unable to fight off infections it normally prevents.
  • Stage 4: Progression from HIV to AIDS - patients may develop increasingly severe opportunistic infections and cancers, leading eventually to an AIDS diagnosis
Stage 1 is the subject of my animation so my next post will revolve around story ideas / narratives along with more research images in response to Peter's answers to my questions.


  1. Hi Paul,

    Thank you very much for your questions - they are very good and I hope I can answer them:
    Does the HIV cell 'mature' when it has infected the cell?
    Yes, it does. You can imagine it as some kind of construction line, in which the different parts are assembled. First, you would probably assemble the genetic elements and then 'wrap' it nicely up.
    Are 'T helpers' white blood cells and do you want the animation to be a process of one of these being infected?
    Yes - T helper cells are indeed white blood cells, which get infected by HIV. I don't want to be too prescriptive for your animation, but I could imagine that the infection of such a cell would be a very nice theme.
    Does the HIV cell actually penetrate the cell membrane?
    Yes, it does. The outer membrane of the virus fuses with the cell membrane (as far as I know). Once this has happened, the genetic material of the virus (the RNA in this case) can be released into the cell.

    Hope this makes sense.

    Best wishes,

  2. That's great, thanks for a speedy response.

    Watch this space...