T cells in blood?

Question

what is T cells in blood. What should be normal values. Apart from HIV does any other illness is dependent on its value. IN HIV cases, what will be T cells value?

Answer 1

Just get an HIV test and either stop worrying or get set to meet your maker. Either way, read Mere Christianity by C.S. Lewis.

Answer 2

All cancers are affected by T Cell counts, as are all immune illnesses and anemia just to name a few T Cell Counts alone will not give you definite answer as to whether you are HIV positive or negative. You can have a high or low T Cell Count and have any number of illnesses, which is why it is important to get accurate information. Don't be nervous if that is a concern. Information is power and the more information you have the better. Unless you have actually tested HIV positive you should not assume that is what is wrong with you (I'm sorry I mean if you are asking personally--I don't mean to ssume I just don't want you to be frightened).

Answer 3

Your immune system contains different types of cells that help protect the body from infection. One of these types of specialized cells are called the CD4 or T-cells. HIV attacks these types of cells and uses them to make more copies of HIV. In doing so, the CD4 cell becomes unable to do its job of protecting the body. At first, the body can make more of these T-cells but eventually the body can't keep up and the number of working T-cells decreases. This weakens the immune system and leaves the body at risk for different types of infections.
On a regular basis, your doctor will draw blood and measure the number of T-cells. The higher the number the better able your immune system to do its job. Most people without HIV have about 700 to 1000 CD4 cells. HIV infected people are considered to have "normal" CD4 counts if the number is above 500.

If the number drops below 200, you are said to have AIDS and your doctor will start you on preventative medications to ward off infections and keep you healthy.

T-cells fight ALL infections though. If you get a virus, your T-cells hunt it down...plug into it...find out what will kill it, and then mutate into whatever type of virus killer it needs to, to kill that virus. With AIDS, the AIDS virus pretty much does the opposite to the T-cell and makes it accept the virus, rather than kill it.

Answer 4

Lymphocytes
Lymphocytes are much more common in the lymphatic system, and include the so-called "killer T-cells". The blood has three types of lymphocytes: B cells, T cells and natural killer cells. B cells make antibodies that bind to pathogens to enable their destruction. CD4+ (helper) T cells co-ordinate the immune response (they are what becomes defective in an HIV infection). CD8+ (cytotoxic) T cells and natural killer cells are able to kill cells of the body that are infected by a virus. T cells are crucial to the immune response because they possess a unique 'memory' system which allows them to remember past invaders and prevent disease when a similar invader is encountered again.

(B cells not only make antibodies that bind to pathogens, but during an attack, some B cells will retain their antibodies to serve as a 'memory' system. This is why we only get Chicken Pox once: the 'memory' system stores the antibodies needed for subsequent infections.)

Hope this can help

Answer 5

T cells are a type of white blood cell that play a central role in cell-mediated immunity. The abbreviation "T" stands for thymus, the organ in which their final stage of development occurs. Although there are several different subsets of T cells, all of them express T cell receptor molecules on their surface.

Cytotoxic T cells destroy virally infected cells and tumor cells, and are also implicated in transplant rejection. Also known as CD8+ T cells, since they express the CD8 glycoprotein at their surface.
Helper T cells, or CD4+ T cells, are the "middlemen" of the immune response. Once activated, they divide rapidly and secrete cytokines that regulate or "help" the immune response. They are also a target of HIV infection, with the loss of CD4+ T cells leading to the symptoms of AIDS.
Regulatory T cells, formerly known as suppressor T cells, are crucial for the maintenance of immunological tolerance. Mutations of the FOXP3 gene can prevent regulatory T cell development, causing the fatal autoimmune disease IPEX.
Natural Killer T cells
γδ T cells
CD4 and CD8 refer to the characteristic glycoproteins on the surface of certain T cells. These CD molecules are convenient diagnostic markers for identifying T cells by flow cytometry.

The ratio between various T-cell concentrations in one's blood is of clinical interest.

Answer 6

T cells are like white blood cells the y kinda fight the HIV.

Answer 7

T cells are a type of white blood cell that play a central role in cell-mediated immunity. The abbreviation "T" stands for thymus, the organ in which their final stage of development occurs. Although there are several different subsets of T cells, all of them express T cell receptor molecules on their surface.

Cytotoxic T cells destroy virally infected cells and tumor cells, and are also implicated in transplant rejection. Also known as CD8+ T cells, since they express the CD8 glycoprotein at their surface.
Helper T cells, or CD4+ T cells, are the "middlemen" of the immune response. Once activated, they divide rapidly and secrete cytokines that regulate or "help" the immune response. They are also a target of HIV infection, with the loss of CD4+ T cells leading to the symptoms of AIDS.
Regulatory T cells, formerly known as suppressor T cells, are crucial for the maintenance of immunological tolerance. Mutations of the FOXP3 gene can prevent regulatory T cell development, causing the fatal autoimmune disease IPEX.
Natural Killer T cells
γδ T cells
CD4 and CD8 refer to the characteristic glycoproteins on the surface of certain T cells. These CD molecules are convenient diagnostic markers for identifying T cells by flow cytometry.

The ratio between various T-cell concentrations in one's blood is of clinical interest.

Contents [hide]
1 T cell development
1.1 Positive selection
1.2 Negative selection
2 T Cell Activation
3 References
4 External links



[edit]
T cell development
T cell precursors originate as pluripotent stem cells in the bone marrow, after which they populate the thymus as immature T cells or "thymocytes." These cells express neither CD4 nor CD8, and are therefore classed as double negative (CD4-CD8-) cells. As they progress through development they become double positive (CD4+CD8+), and finally single positive (CD4+CD8- or CD4-CD8+) cells. About 98% of thymocytes die in the thymus by failing either positive selection or negative selection, while the other 2% survive and leave the thymus to become mature T cells.

[edit]
Positive selection
After populating the outer region of the thymus (cortex) as double negative thymocytes, double positive cells move deeper into the cortex where they are presented with antigens complexed with MHC molecules by cortical epithelial cells. Only those cells which bind the MHC/antigen complex with adequate affinity will receive a vital "survival signal". The other cells go into apoptosis and their remains are engulfed by macrophages. This process is called positive selection.

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Negative selection
Cells that survive positive selection move towards the boundary of the thymic cortex and thymic medulla. In the medulla, they are again presented with antigen in complex with MHC molecules on the surface of medullary epithelial cells. If these antigens are recognized with high affinity, they die by apoptosis. This process is called negative selection - an important mechanism of immunological tolerance.


Hormonal substances (thymosin, interferon γ, interleukins, colony stimulating factors, thymopoetin, etc.) secreted by epithelial cells within the thymic (Hassal's) corpuscles promote the process of thymic education. Not only is the differentiation of T cells regulated by thymic epithelial cells, but T cells influence the architecture of the thymus itself.

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T Cell Activation
Although the specfic mechanisms of activation vary slightly between different types of T cells, the following two-signal model is generally true for most:

The interaction between TCR molecules and specific MHC/antigen complexes on APCs delivers signal 1 into the T cell.
Costimulatory interactions between CD28 molecules on the T cell and B7 molecules on the APC deliver signal 2, activating the T cell. Without costimulation a T cell will become functionally inert (anergic).
T cell activation can be gauged using the ELISPOT technique, which can determine the percentage of T cells that secrete any particular cytokine

Answer 8

Please see the webages for more details on T (thymus derived) Lymphocyte count and Helper T cell.