Working Toward a Cure: HIV Gene Therapy

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  • Keep Your Genes to Yourself, HIV

    Keep Your Genes to Yourself, HIV

    The human immunodeficiency virus (HIV) attacks the immune system. It makes people sick by infecting their CD4 cells, which are also called helper cells. The virus grabs onto a cell and injects its genetic signature. It transforms the helper cell into a machine that replicates the deadly virus.

    But scientists have learned more about how HIV cracks a cell's code, gets inside, and does its damage. Thanks to a now-famous man from Seattle, known as “The Berlin Patient,” they know a cure is possible and continue to search for it.

  • Just Who Is 'The Berlin Patient?'

    Just Who Is 'The Berlin Patient?'

    Timothy Brown had HIV when he underwent a stem cell transplant for acute myeloid leukemia (AML) in 2007. Stem cells have a complete genetic blueprint and can become any type of cell.

    Not only did the transplant (which had to be repeated) cure Brown of AML, but he also became free of HIV. Scientists believe he is the only person ever to be functionally cured of HIV.

    Treated in Berlin, Brown's doctors chose a donor who had a mutation called Delta 32 on a stem cell protein. These proteins, called CCR5, are needed for HIV to get into a cell.

  • Immunity and 'CCR5 Delta 32'

    Immunity and 'CCR5 Delta 32'

    CCR5 Delta 32 has a mutation that prevents CCR5 from letting HIV inside a cell. People who inherit one copy of CCR5 32 (from one parent) usually receive substantial, but not total, immunity from HIV. Those who get a copy from both parents usually have total immunity.

    Reports of the prevalence of one copy of this gene vary, but one study reports that about 9 percent of people of European descent have one copy.

    In searching for a potential HIV cure, researchers are looking for a way to genetically engineer what this and other genes do to seemingly grant immunity.

  • New Drugs on the Way

    New Drugs on the Way

    Although a cure could still be many years away, HIV genetic therapy already has led to new medications. A new class of drugs called integrase inhibitors has emerged. These drugs cripple the protein needed to help HIV get inside a CD4 cell and hijack it.

    Two integrase inhibitors for HIV already are on the market in the United States. Others are in the pipeline. These drugs are taken in combination with existing antiretroviral therapy (ART).

  • Search and Destroy

    Search and Destroy

    Genetically designed poisons, or immunotoxins, are also being developed to kill HIV. In January 2014, scientists found another possible weapon against HIV. They reported that a genetically modified compound called 3B3-EP38 served as a guided missile, carrying a payload toxin on an HIV search and destroy mission.

    The 3B3 is an antibody that zeroes in on an HIV-infected cell expressing a certain protein. The EP38 is a bacterial toxin that delivers the dose. Researchers reported some success experimenting with 3B3-EP38 in mice.

  • A National Commitment to a Cure

    A National Commitment to a Cure

    Modern antiretroviral therapy (ART) keeps patients healthy for decades, but the patients have to take the medication forever. Once somebody stops ART, the virus roars back. The virus can also develop a resistance to the drugs.

    Research, such as genetic research, is expensive. It involves manpower and technology. In December 2013, the National Institutes of Health (NIH) announced plans to provide an additional $100 million for HIV research.

  • Technology Fuels Research

    Technology Fuels Research

    Editing and modifying genes, known as gene editing, has led to promising new discoveries for treating HIV. In gene editing, scientists are able to modify or disable parts of genes, which can influence cell function.

    In a study published in 2014, researchers reported that they effectively edited the gene that controls CCR5, rendering the gene dysfunctional. As mentioned earlier, CCR5 is needed for HIV to enter cells. Disabling it is a blow to HIV.

    The study found that editing the gene in people with HIV was safe, within the limits of the study. If gene editing proves effective, it could mean patients might be able to avoid expensive antiviral drugs.

  • Collaborating for a Cure

    Collaborating for a Cure

    Gene therapy and research is another weapon in the scientific and medical community's arsenal against HIV. Dozens of public and private institutions, both for-profit and academic, have begun to work together. The goal to obliterate the disease appears to be more and more possible.

    Tests are available to find out what genes a patient with HIV may have. If you’re interested in gene therapy to treat your HIV, discuss the therapy with your doctor.