The lack of effective vaccines against pathogens has stimulated the interest in the development of a topical microbicide. Microbicides are designed to inhibit HIV infection by directly inactivating the virus or interrupting the attachment of the virus to the host cells and replication thereof. To be able to develop an effective microbicide, one has to understand the means by which HIV infiltrates the genital mucosa, the role of dendritic cells, as well as the process of transportation of the virus to the lymph nodes (DU TOIT et. al., 2009).
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...
It is postulated that HIV-1 infections promote HHV-8 replication indirectly by suppression of host immune systems. KS is thought to begin with micro-vascular lesions mediated by different environmental factors for each of the four categories of KS. One of these factors is abnormal cytokine production; in HIV-1 associated KS, this includes an increase in inflammatory cytokines, such as IFN , TNF , and IL-7 that are enhanced by Tat of HIV-1. Tat which is essential for HIV-1 replication is released and taken up by other cells, where it inhibits T-cell proliferation and promotes abnormal cytokine production, adhesion, and growth.
Human Immunodeficiency Virus, also known as HIV, is a virus that attacks the immune system. It invades our T cells and then makes more copies of itself. It then destroys them and our immune system can no longer fight of other infections or diseases, which can lead to AIDS. There are three major routes it is transferred by. The first route is sexual intercourse through the vaginal, rectal, or penile tissues. The second route is a direct injection with HIV-contaminated drugs, needles, syringes, blood or blood products. The third major route HIV can be transmitted is from an HIV-infected mother to the fetus in the uterus or even through breast-feeding. Once the virus is transmitted to someone else, it attaches immune system cell called a dendritic cell. These cells are located by the mouth, vagina, rectum, and penis. The cells then transport the virus from the where the infection is to the lymph nodes where it also infects other immune system cells. Once inside the cell, the virus turns RNA into DNA, and then makes its way to the cells nucleus. The HIV weakens the immune system. The infected HIV cells convert into the messenger RNA then it is transferred outside the nucleus and is used to make more HIV infected cells.
AIDS (acquired immune deficiency syndrome) is a disease of an individual’s immune system caused by HIV-1 (human immunodeficiency virus 1). HIV-1 is a retrovirus of the lentivirus subfamily. This virus is atypical in that it does not require mitotically active cells to reproduce. Reproduction of the viral nucleic acids occurs in the nucleus of infected cells. Until recently it was believed that AIDS related deaths as a result of HIV infection were caused primarily by opportunistic infections, usually bacterial or fungal, gaining a foothold in an immuno-compromised individual. Many of these secondary infections are the result of T-cell mediated immunodeficiency induced by HIV. The sequels of HIV infection often leads to a neuropathological state as a result of unusual secondary infections such as Toxoplasmosis. Postmortem studies have demonstrated that in addition to secondary infection, neurological manifestations may be due to vascular events, tumors (CNS lymphoma) and direct HIV-1 infection. 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.
The Acquired immune deficiency syndrome (AIDS) was first identified as a distinct new disease in 1981. In 1983 HIV was identified at the causative agent for AIDS. The mean time from HIV infection to AIDS is approximately 10 years. There is no effective medicine to cure it and the infected individuals do not recover: that is, they continue to be infectious throughout their lives. HIV infection is a complex mix of diverse epidemics within and between countries and regions of the world, and is undoubtedly the defining public health crisis of our time. The AIDS is a disease of the human immune system caused by the human immunodeficiency virus (HIV). It becomes an important infectiousdisease in both the developed and developing countries. AIDS is a fatal disease which destroys the human’s immune system, leaving the victim vulnerable to a host of life threatening infectious, neurological disorders and unusual malignancies. The AIDS epidemic is one of the most destructive health crises of modern times, ravaging families and communities throughout the world. By 2012, more than 36 million people had died, an estimated 75 million were living with HIV. The most common ways in which HIV is spreading throughout the world include (i) sexual intercourse, (ii) sharing contaminated blood products or needles and (iii) by vertical transmission from infected mothers to their new born during pregnancy, labor (the delivery process) or breastfeeding. HIV infection is generally a slow progressive disease in which virus number in the body is a major indicator of the disease stages. In a normally healthy individual’s peripheral blood, the level of CD4+ T-cells is between 800 and 1,200/mm3 and once this number reaches 200 or below in...
AIDS stands for acquired immunodeficiency syndrome and is caused by human immunodeficiency virus, or HIV. HIV is transmitted through blood and bodily secretions, specifically sexual secretions (Handsfield 157). HIV has an incubation period of 10-20 days after one is exposed to the virus (Handsfield 161), and can result in a variety of symptoms including an unexplained fever, a rash, or unexplained weight loss (Handsfield 163). If a patient has reached a diagnosis of AIDS, it means that person has reached a stage 3 HIV infection. This means the patient’s body has less than 200 lymphocyte cells per mm3 (Handsfield 162). Lymphocytes are a vital part of the immune system (Encyclopedia Britannica) and without them one is susceptible to many respiratory diseases, bacterial infections, and even certain types of cancer. These are things that a healthy person can fight off, but they end up being the probable cause of death in a patient with AIDS (Handsfield 162). AIDS and HIV are more commonly found among men that have sex with other men. This group is often referred to as MSM for short (Handsfield 157). The r...
...antibody responses and protect against HIV infection, boosting up the T cell response to control viral replication and handling the problem of enormous HIV diversity are crucial elements in the pursuit of an HIV vaccine. Immune correlates of the modestly efficient RV144 trial have identified the V1V2 region to be the target of neutralizing antibodies and follow up studies are underway to evaluate multiple prime-boost regimens which will generate more data and insights in to the development of a vaccine. Recent discovery of bnAbs has provided a new and exciting avenue for designing an efficient vaccine. Unique approaches like B-cell lineage vaccine and AAV vector vaccines to elicit bnAb responses are being studied. By and large, this is a tremendously motivating period for HIV vaccine researchers, one that spawns more optimism markedly higher than in preceding years.
HIV (Human Immunodeficiency Virus) is a retrovirus which infects, impairs or destroys the cells of the immune system and functions. Progression of the infection (severe immunodeficiency) leads to weaker immune system rendering an individual susceptible to more infections. These infections are termed opportunistic infections. At its most advanced phase, HIV is called AIDS (Acquired Immunodeficiency Syndrome) and characterised by cancers related to HIV or any of twenty opportunistic infections (WHO, 2013; WHO 2014a).
It contains in the nucleus two single RNA chains. This virus begins by flouting the immune system protective barriers and continues then to destroy it to the point that the organism interfered becomes exceedingly vulnerable to infections that will otherwise not affect him or her. It is attach to the host cell by binding to a receptor called CD4 and also to a co-receptor that may be CCR5 or CXCR4.The two types of HIV reservoirs are the cellular and the anatomical. The combination of these reservoirs with latent infection causes persistent viremia, regardless of treatment with antiretroviral drugs. The way that the immune system reacts to these types of contamination comprises the assembly of virus-specific antibodies and cytotoxic T cells with the purpose of exterminating the cells that the virus has infected. Since HIV replication is error-prone, it has an elevated variability level that can be produce by mutation and / or by recombination. There are tow types of HIV: HIV-1 (most common) and HIV-2 (Usually in some areas of Africa). The first one is distributed into three units. Unit M is the most common worldwide; this is additionally divided into ten to twenty