In humans, HIV is known to infect T-lymphocytes within the body binding to the CD-4 receptors present on the cell surface, but in the brain, recent studies have suggested that microglial cells and macrophages serve as the reservoirs of HIV. Direct central nervous system infection by HIV results in a condition known as AIDS Dementia Complex and as such will serve as the topic of this paper. AIDS Dementia Complex is defined as a constellation of signs and symptoms characterized by cognitive and motor decline. HIV-1 infection occurs early in the course of the disease and may be the sole symptom of infection. HIV encephalopathy is the most common neurological disorder of HIV positive individuals, even more common than neurological opportunistic infections.
This system involves the body's ability to distinguish cells that are part of the body from those that have found their way in and are harmful. Most of these unwanted substances are viruses, bacteria, and other type of disease causing organisms. When a cell in our body has become infected or has become cancerous it’s surface changes. This is how the immune system can tell good cells from bad ones (the markings on the surface.) Once a bad cell has been recognized our bodies sends cells to destroy the damaged cell and prevent the spread of whatever caused the damage in the first place.
Their destructive activity is limited to cells that are either infected with or producing a specific antigen. Cell meditated immune responses resist invaders that reproduce within the body cells such as viruses. Cell meditated responses may also destroy cells making mutated forms of normal molecules as in some cancers. Diseases and how they can be control. When people refer to pathogens, they are talking about bacteria that cause disease.
EBV is a herpes virus. In vitro, EBV only infects human B-lymphocytes. This viral infection results in lymphocyte proliferation and immunoglobulin secretion. The virus usually remains dormant, but can be activated using certain chemicals or when subjected to certain bodily conditions. To understand how this virus affects the body, we must first have a brief overview of the body and it’s immune system.
The herpes viruses can do this over and over again. They hide in nerve tissue until prompted to erupt leaving painful ulcers as host tissue is destroyed. Human papilloma virus—HPV--causes genital warts and predisposes its victims to cervical cancer. Likewise, hepatitis viruses, especially hepatitis C can leave a patient vulnerable to liver cancer. Other cancers in humans are also known to be caused by viruses.
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.
HIV is the human immunodeficiency virus that causes AIDS. A member of a group of viruses called retroviruses, HIV infects human cells and uses the energy and nutrients provided by those cells to grow and reproduce. AIDS (acquired immunodeficiency syndrome) is a disease in which the body's immune system breaks down and is unable to fight off certain infections, known as "opportunistic infections," and other illnesses that take advantage of a weakened immune system. When a person is infected with HIV, the virus enters the body and lives and multiplies primarily in the white blood cells. These are the immune cells that normally protect us from disease.
Viruses can effect humans, animals, plants, and bacteria. The reproduction cycles for viruses are the lytic cycle and the lysogenic cycle. In the lytic cycle there is attachment, when the virus’ receptor combines with the host, penetration, when the DNA is injected into the host cell, biosynthesis, when the virus takes over the host cells functions and makes it replicate the viral DNA and manufacture the capsids, maturation, when the DNA and capsids are assembled, and release, when the fully formed capsids are released into the host organism to infect more host cells. HIV, the flu, and the common cold are examples of diseases caused by viruses. HIV is caused by a retrovirus that goes through the lysogenic cycle.
It spreads like wildfire by the dendritic cell carrying over to the human lymph nodes that can infect other immune system cells (aids.gov, 2009). The transmission of this virus attacks cells in your body that can spread into your immune system that can harm the way your body fights against bacteria and other sicknesses. The spread of HIV can be broken down into six main processes that repeat in a cycle to duplicate itself causing the virus to overtake the human body. It has one goal which is to infect the CD4 lymphocyte which is a T-cell that helps it reproduce and spread. As stated HIV hooks onto a T-cell then it allows itself to be released into the cell called binding and fusion (aids.gov, 2009).
In the case of HIV, the virus has a cell membrane with embedded viral proteins that enables it to do so, but this works only when it binds with two specific receptors. One is called the main receptor, and the other a coreceptor. There are two types of HIV; M-tropic and T-tropic. The M-tropic variant targets macrophages while the T-tropic variant targets the T cells.