Topic : HIV a perfectly evolved stealthy intruder.
Title: Mechanisms of CD4+ T cells depletion during HIV-1 infection.
Introduction
The human immunodeficiency virus (HIV) is a retrovirus,which affects the human immune system. HIV infects cells such as macrophages, dendritic cells,and helper T cells ,most commonly CD4+ T cells. The virus invades cells that are vital for the immune system to work properly.HIV causes depletion of immune cells as a result of viral replication.The virus causes persistent infection of the immune system, leading to low counts of CD4+ T cells .Helper T-cell depletion occurs during HIV-1 infection.Low levels of such cells are brought on by different mechanisms during the infection. Although the actual pathway that causes cell death within the host is not fully understood , a few mechanisms seem to play an important role . These mechanisms include cell apoptosis, viral induced cell death of infected bystander cells, and elimination of infected cells caused by CD8 killer T-cells. With low levels of CD4+ T cells , the immune system does not respond properly to pathogens, therefor the host becomes susceptible to infections. These infections include opportunistic infections and tumors that would otherwise be harmless to humans. Individuals infected with the virus , if untreated, have low levels of CD4+ cells leading to progressive failure of the immune system, resulting in the development of AIDS( acquired immunodeficiency syndrome). AIDS is the final stage of the disease , but it is not the cause of death . Instead, the arising opportunistic infections are life threatening to individuals with depleted immune systems.CD4+ T cell depletion is progressive throughout HIV-1 infection. Direct and indirect cel...
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...he majority of these cells are found in the bone marrow,thymus ,lymphoid tissues ; lymph nodes,spleen,mucosa,and tonsils. Genetic research indicated that most CD4+ T Cells that are killed by HIV-1 infection are bystander uninfected cells.HIV infected individuals show high depletion levels of the CD4+ T cells . In tonsils and spleens these cells get infected by the virus, but only a minute ( about 5-8%) portion of those cells die by direct infection. Though mostly in HIV infected individuals most of these cells are killed in these areas ( about 99% of the CD4+ T cells die).In late stages of the disease , all the areas mentioned previously have almost no new production of CD4+ T cells, due to continued destruction.
The mechanisms of CD4+ T cell death by bystander uninfected cells does not require the cell to be infected but to be in proximity of infected dying cells.
To be able to determine which task the immune system needs to take to fight off the pathogen, it must be able to differentiate between self and non-self-substances. The immune system gets activated by the non-self-substances called antigens. The antigens attach to special receptor sites on defense cells which starts cell processes. If the body has come in contact with the antigen before, it will be able to respond to it more quickly (PubMed Health).
The Vel' d'Hiv Roundup came at a horrible point in the history of the world. The Holocaust is hands down one of the worst tragedies to have happened ever. When one thinks of the Holocaust you think of the Nazis and all the wrong they did but it wasn’t just the Nazis they had to have help. The Vel d’Hiv Roundup is an example of the help the Nazis received.
Everyday researchers have proposed new methods of how to control the HIV virus from turning into AIDS. A combination of effective HIV medicines help stop the formation of new copies of HIV as it reproduces in your body. This technique helps to keep your CD-4 cell count up and your viral load down. CD-4 cells are one type of immune cells that assist to fight off the virus, the higher your count the stronger your immune system (Nakashima 77). Whereas, your viral load is a measure of HIV in your blood and your treatment goal is to have the lowest viral load possible. People with higher viral loads tend to progress to AIDS and become sick sooner than those with lower viral loads (Nakashima 80). Successful HIV medications can prevent other infections common with AIDS and can help you live longer.
The etiologic agents of the neurologic disease associated with HIV and AIDS are many. Opportunistic infections- cryptococcus, toxoplasmosis, cytomegalovirus, are a few of the organic causes of neurologic disease in AIDS patients, but will not be the main focus of this paper. The human immunodeficiency virus in itself is implicated in much of the neurological manifestations of the disease, and it is the effects of the presence of the virus within the central nervous system which is of interest to me in this paper.
T cells assist B cells to rid foreign cells, and turn into memory cells (Joanne M. Willey, 2014). The T-Helper cell dictates growth and variation factors (Joanne M. Willey, 2014). This decides whether you will have a strong or weak immune system (Joanne M. Willey, 2014). The cytotoxic cells are accountable for lytic enzymes and proteins (Joanne M. Willey, 2014). They kill or change injected cells (Joanne M. Willey, 2014). The suppressor cells are also known as 911 and relay a rapid response to reinfection with the same cell (Joanne M. Willey,
This can trigger cytotoxic T cells to kill cancer cells with the same antigen – often HPV viral proteins in cervical cancer. T cells may not be activated to their full potential – recall that the inhibitory receptor CTLA-4 in T cells sends a stronger signal than CD28, the activating receptor.
Human immunodeficiency virus (HIV) is a retro virus that causes AIDS. HIV is a virus that can only be contracted between human to human. HIV weakens your immune system because this virus is destroying cells that fight diseases and infection in your body. A virus can only produce itself by taking over a cell in the body of its h...
Human Immunodeficiency Virus (HIV) leads to the life threatening Acquired Immunodeficiency Syndrome (AIDS). HIV only lives in the blood and other bodily fluids. Concentrations of HIV are small in vomit, sweat, tears, and saliva and cannot be transmitted by those fluids. The main transmission is through fluids like semen, vaginal fluids, and rectal mucous during sexual contact, breast milk and amniotic fluid passing to children, and blood during transfusions and exposure. Beginning stages of HIV start with the acute infection. During the first 2 weeks to a month after exposure to the HIV infection, most infected individuals with display symptoms of a severe flu. The symptoms include fever, swollen glands, sore throat, rash, muscle and joint aches and pains, fatigue, and headache. The early period of infection is known as the “acute retroviral syndrome” (Stages, 2013). Once the virus is out of the acute stage it enters into the latency stage where it continues to replicate but no symptoms are shown. As the infection progresses and the immune system beco...
People infected with Human Immunodeficiency Virus (HIV) have a sequential destruction of CD4 T cells which always lead to a weakening of the immune system. Despite the reduction of CD4 T cells, the macrophages and dendritic cells are also affected by HIV. Moreover, HIV causes a dysfunctionality in B cells, CD8 T cells, and innate immune system cells (Shipley, 2013). For instance, the reduction of perforin production and IFN-γ secretion in CD8 T cells cannot help effector T cells to destruct virus-infected cells (Kuerten et al., 2008). The reduc...
HIV affects the immune system, especially a type of T cells (CD4 cells). Over time, HIV destroys the overal...
The Human Immunodeficiency Virus is responsible for 1.6 million deaths annually according to the World Health Organization (WHO). It is a retrovirus, which infects the body's T-lymphocytes and destroy it, thus rendering the body susceptible to numerous diseases, especially viral diseases. Due to the fact that the body's immune system is compromised, opportunistic diseases begin to occur. In today's society, many persons engage in sexual intercourse with multiple partners and without condoms, therefore placing themselves at increases risk of sexually transmitted diseases such as HIV. Most individuals who are infected with HIV, develop AIDS at some point in time.
If you have been diagnosed with AIDS, you need to know about the effects that AIDS can have on your nervous system. There are two parts to the nervous system: the central nervous system and the peripheral nervous system. The central nervous system is your brain and spinal cord. The peripheral nervous system is all the nerves that go out to your body parts and return signals to your brain and spinal cord. AIDS can damage both parts of your nervous system.
Acquired Immunodeficiency Syndrome (AIDS) first came to light in 1981. There has been a long and arduous global effort on the prevention of HIV/AIDS. HIV is a virus that is spread through body fluids that affect the specific T-cells of the immune system. Without treatment HIV infection leads to AIDS and there is no cure for AIDS. HIV infection can be controlled and the importance of primary pre...
Adaptive immune system happens much quicker to the presence of an “infection creating potent mechanisms for neutralizing or eliminating the microbes. There are two types of adaptive immune responses: humeral immunity, mediated by antibodies produced by B lymphocytes, and cell-mediated immunity, mediated by T lymphocytes.”
Acquired immune deficiency syndrome (AIDS) is a fatal physical condition that is caused by the human immunodeficiency virus (HIV). The virus damages the human body’s immune system, so that the body cannot protect itself from bacteria, viruses, and prions that cause diseases. With severely lowered defenses, AIDS patients die from common illnesses such as pneumonia, diarrhea, cold, and tuberculosis. The HIV virus does not directly attack its victim; the disease that patients suffer from after receiving the virus is what hurts and kills them.