HIV & AIDS

Release of inhibitory pathways may promote immune response to HIV

Recent work from the laboratory of Elena Martinelli, Ph.D., MPH, professor of Medicine in the Division of Infectious Diseases and of Microbiology–Immunology, has discovered how inhibiting an immune cell singling pathway ...

HIV & AIDS

New research advances potential HIV cure strategy

Published in the Journal of Infectious Diseases, new research led by the University of Minnesota Medical School offers a new avenue of hope in the fight against chronic human immunodeficiency virus (HIV) infection.

Medical research

Researcher explores sex-specific features of HIV

Early in her career, Johns Hopkins physician-scientist Eileen Scully began to explore ways that viral infections such as HIV, SARS-CoV-2 and tuberculosis manifest differently in individuals. One particular interest: The differences ...

Medical research

HIV: Early treatment is one key to remission

People living with HIV need to take antiretroviral treatment for life to prevent the virus from multiplying in their body. But some people, known as "post-treatment controllers," have been able to discontinue their treatment ...

HIV & AIDS

Unlocking the mechanisms of HIV in preclinical research

Mayo Clinic researchers have unraveled the molecular mechanisms that affect which cells infected with human immunodeficiency virus (HIV) die and which survive, a discovery heralded as a step toward eliminating all HIV-infected ...

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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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