A 'biomultimeter' to measure RNA and protein production in real-time

Builders of genetic circuits face the same quandary as builders of digital circuits: testing their designs. Yet unlike bioengineers, engineers have a simple and universal testing tool—the multimeter—that they can touch ...

New HIV model suggests killer T cell for vaccine

Limited success in modelling the behaviour of the complex, unusual and unpredictable HIV virus has slowed efforts to develop an effective vaccine to prevent AIDS.

HIV's ancestors 'plagued first mammals'

(PhysOrg.com) -- The retroviruses which gave rise to HIV have been battling it out with mammal immune systems since mammals first evolved around 100 million years ago - about 85 million years earlier than previously thought, ...

Regulatory role of key molecule discovered

Discovery by Hebrew University of Jerusalem researchers of an additional role for a key molecule in our bodies provides a further step in world-wide efforts to develop genetic regulation aimed at controlling many diseases, ...

Scientists identify new virus-killing protein

A new protein called KHNYN has been identified as a missing piece in a natural antiviral system that kills viruses by targeting a specific pattern in viral genomes, according to new findings published today in eLife. Studying ...

New imaging reveals previously unseen vulnerabilities of HIV

Imagine that HIV is a sealed tin can: if you opened it, what would you find inside? An international team led by researchers at the University of Montreal Hospital Research Centre (CRCHUM), Tufts University School of Medicine, ...

How HIV DNA is blocked from entering the cell nucleus

Multiple components of the nuclear pore complex and nuclear import machinery enable a protein called human myxovirus resistance 2 (MX2) to inhibit HIV-1 infection, according to a study published November 29 in the open-access ...

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HIV

Human immunodeficiency virus (HIV) is a lentivirus (a member of the retrovirus family) that causes acquired immunodeficiency syndrome (AIDS), a condition in humans in which the immune system begins to fail, leading to life-threatening opportunistic infections. Infection with HIV occurs by the transfer of blood, semen, vaginal fluid, pre-ejaculate, or breast milk. Within these bodily fluids, HIV is present as both free virus particles and virus within infected immune cells. The four major routes of transmission are unsafe sex, contaminated needles, breast milk, and transmission from an infected mother to her baby at birth (Vertical transmission). Screening of blood products for HIV has largely eliminated transmission through blood transfusions or infected blood products in the developed world.

HIV infection in humans is now pandemic. From 1981 to 2006, AIDS killed more than 25 million people. HIV infects about 0.6 percent of the world's population. In 2005 alone, AIDS claimed an estimated 2.4–3.3 million lives, of which more than 570,000 were children. A third of these deaths are occurring in sub-Saharan Africa, retarding economic growth and increasing poverty. According to current estimates, HIV is set to infect 90 million people in Africa, resulting in a minimum estimate of 18 million orphans. Antiretroviral treatment reduces both the mortality and the morbidity of HIV infection, but routine access to antiretroviral medication is not available in all countries.

HIV primarily infects vital cells in the human immune system such as helper T cells (specifically CD4+ T cells), macrophages, and dendritic cells. HIV infection leads to low levels of CD4+ T cells through three main mechanisms: firstly, direct viral killing of infected cells; secondly, increased rates of apoptosis in infected cells; and thirdly, killing of infected CD4+ T cells by CD8 cytotoxic lymphocytes that recognize infected cells. When CD4+ T cell numbers decline below a critical level, cell-mediated immunity is lost, and the body becomes progressively more susceptible to opportunistic infections.

Eventually most HIV-infected individuals develop AIDS. These individuals mostly die from opportunistic infections or malignancies associated with the progressive failure of the immune system. Without treatment, about 9 out of every 10 persons with HIV will progress to AIDS after 10–15 years. Many progress much sooner. Treatment with anti-retrovirals increases the life expectancy of people infected with HIV. Even after HIV has progressed to diagnosable AIDS, the average survival time with antiretroviral therapy (as of 2005) is estimated to be more than 5 years. Without antiretroviral therapy, death normally occurs within a year.

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