HIV and Immune system

  • HIV eventually destroys many of the white blood cells, which protect us against disease.
  • HIV infection leaves people helpless against many other serious infections and cancers.

  • Different viruses invade different kinds of cells. HIV invades and destroys helper T cells, the very cells that direct the body's defenses. By destroying helper T cells, HIV disables the entire immune system that protects us against disease.
  • Lymphoid organs play a central role in HIV infection.
  • Know Our Body's Defense System: The immune system is made up of many different kinds of white blood cells. White blood cells work together to protect us against disease-causing germs. White blood cells defend against germs.
  • The RBC carries heme and iron that help in carrying oxygen around the body. The WBC fights against infection and there are many sub-types of WBC.
  • Macrophages identify germs - When a germ invades our bodies, macrophages gobble up the germ and display its surface shape, or antigen, for other immune cells to see.
  • Helper T cells direct the defense - Helper T cells spot the foreign antigen on the macrophage and begin to multiply. They alert other white blood cells and direct the body's defense.
  • Killer T cells destroy germs Alerted by helper T cells; killer T cells multiply and destroy the invading germs.
  • B cells make antibodies - B cells start to make chemicals called antibodies. Antibodies lock onto foreign antigens making it easier for other immune cells to destroy them.
  • Working together, our white blood cells can usually destroy invading germs.

T-cells and HIV infection

  • There is a significant drop in number of circulating CD4 T cells at this early stage.
  • An immune response to HIV occurs 1 week to 3 months after infection, when the levels of CD4 cell increases. But the immune response is unable to clear the infection completely, and HIV-infected cells persist in the lymph nodes.
  • This period of clinical latency may last for as long as 10 years. Although very few infected cells are in the blood.
  • HIV found in patients with late-stage disease is usually much more virulent and harmful than the strains of virus found early in infection.
  • Decrease of CD4 T-lymphocytes causes a decrease in Immune response and affects the lymphoid and non-lymphoid cell functions.

Further Reading:

HIV and B-Cell function:

  • AIDS infected persons show an abnormal B cell function.
  • It produces an inability to mount an adequate immunoglobulin M (IgM) response against the HIV.

Monocytes and HIV:

  • Monocytes and macrophages play a major role in the spread and pathogenesis of HIV infection.
  • These phagocytic cells can engulf the virus.
  • Monocytes express the CD4 surface antigen and therefore bind to the envelope of HIV.
  • The infectivity of monocytes with HIV suggests that the monocyte serves as a major reservoir for HIV in the body.
  • Neurologic abnormalities are common in AIDS
  • HIV encephalopathy, myelopathy, peripheral neuropathies, and most serious, AIDS dementia complex.
  • gp120, may be involved in tissue damage without actual infection of all cells.
  • It is speculated that gp120 may activate macrophages, microgilia, and astrocytes and cause the release of cytokines and neurotoxins that injure neighboring neuronal cells.
  • In HIV infected individual, a wide range of invivo antigenic stimuli seems to serve as cellular activators.
  • Other concomitant viral infections - EB virus, Cytomegalo virus, Herpes simplex virus, or hepatitis B virus can act as cofactors for AIDS.


Jeremy1977 Wednesday, May 22, 2013

I was told that only after 7 weeks of having sex with an HIV positive person the virus can be detected in a healthy [HIV negative] person. During this 7 weeks period the HIV multiply and grows. My question is, during this period, can a strong immune system can fight off the HIV and defeat it, kill it? For example, if I'll eat only healthy food, exercise, etc' - and have a strong immune system, I can prevent myself from having AIDS? Even though I had unprotected sex?

tiffy Saturday, March 26, 2011

youths aged between 13 to 24 are at the centre are infected with HIV 15 million youths worldwide have HIV and some youths dont even know they have HIV, some people have no signs of HIV until later stages antibodies are testing to see if a person is HIV postive

Yoggoth Tuesday, August 17, 2010

According to my calculations, at least a billion people are now infected, and a million more are being infected every day. Can you comment on this?

iha_chauhan Saturday, November 7, 2009

hi people! AIDS can affect anyone anywhere. The best way is to protect yourself from any kind of unprotected exposure like sex workers, multi-partner sex, syringes, blood transfusion etc. Though women are more susceptible, men are equally receptable to infection. Symptoms as such could'nt be monitored. Its usually associted with decreased immunity with consecutive infections. The virus may not show itself to a maximum of 10 years. The only way is to check urself for HIV virus. Bye . Have a safe life

godsooh Thursday, May 14, 2009

hi, could you tell me a little about the symptoms of a new HIV. does HIV has movement ? does it change the color of urine ? does it cause eternal heat ? does it has a biting movement in the reproductive system ? please, answer me because i am worried!

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