DNA Ink
by Jennifer Altavilla

If you thought you would never see your mother get a tattoo, think again. A few decades from now, Mom might even encourage you to get inked. Thanks to German scientists, the tattoo needle may no longer be just an artist's tool, but a healthcare implement. More precisely, an instrument for injecting DNA vaccines.

As Matt McGrath recently reported in his BBC News article, "Tattoos May Help Deliver Vaccine," researchers at the German Cancer Research Center in Heidelberg have discovered that vaccines injected with a vibrating tattoo needle elicit a stronger immune response than one injected with an ordinary needle. In fact, tests on mice show that this injection method produces sixteen times more antibodies than one injected in the customary manner. The higher antibody level is due to the fact that the vibrating needle causes a larger, more inflamed wound than a common needle. The wider and deeper a wound is, the faster antibodies - proteins found in body fluids that attack foreign objects - rush to the scene.

The discovery of the medical benefits of the tattoo needle could finally catapult the DNA vaccine onto the mainstream pharmaceutical market, says Alexis Madrigal of Wired.com. The vibrating needle is the first DNA vaccine injection method that efficiently accelerates immune response, which does not occur naturally in DNA vaccines. A DNA vaccine works differently because it does not contain antigens - immune response proteins - like other vaccines, but rather a DNA fragment that codes for the antigens. A DNA vaccine not only stimulates the production of antibodies like common protein-based vaccines, but also catalyzes cell-mediated immunity, which is required to protect against certain viruses - HIV-1 for example - that live within the body's cells. The DNA vaccine induces such cell-mediated immunity by stimulating the production of T-lymphocytes, better known as killer-T cells. Killer-T cells, which are produced in bone marrow, kill the body's own cells that have been invaded by a virus or bacteria, thus preventing the reproduction and transmission of infected cells to other areas of the body.

DNA vaccines are valuable not only because they are able to protect against both extra-cellular and intra-cellular viruses, but because they are cheap to produce and versatile. DNA vaccines, composed of virus genes encapsulated in a circular structure called a plasmid, are grown synthetically within bacteria cultures in large batches. In contrast, protein-based vaccines—created by injecting fertilized chicken eggs with an active virus, and then killing and purifying it—can only be produced one or two doses at a time. DNA proteins are also chemically stable, so they can be grown in almost any environment. Most importantly, DNA fragments can be artificially programmed to mimic whatever virus scientists want to vaccinate against. If the tattoo needle is found to be a viable transmission method for DNA vaccines, then pharmaceutical companies will be able to afford to research cures for HIV-1, SARS, and cancer, and also therapeutic remedies for AIDS, hepatitis B, and malaria. According to a National Academy of Sciences of the United States report by Michael Sela and Maurice Hilleman, DNA vaccines implanted with tattoo needles might also be able to provide therapeutic relief for people with autoimmune diseases such multiple sclerosis.

Presently, however, the scientists of the German Cancer Research Center believe DNA vaccines are more appropriate for the routine mass vaccination of cattle and other animals. McGrath says the scientists are more interested in the “commercial application” of DNA vaccines—as lead researcher Martin Muller calls it—because they believe the pain of tattooing may restrict their widespread use. General apprehension and skepticism about tattooing might also contribute to the commercial failure of tattoo administered DNA vaccines.

Still, the advantages of DNA vaccines are too great to say for certain that they will never find their way onto the market. In 2006, pharmaceutical giant Pfizer signaled a dedication to DNA vaccine research and development by buying out PowerMed, a DNA vaccine company. If companies like Pfizer are able to create viable therapeutic cancer or AIDS vaccines, people will use them, even if they have to endure the pain of the tattoo needle. For cancer patients undergoing chemotherapy and radiation, or AIDS patients wracked with opportunistic infections, a few needle pricks are a small price to pay for relief. Perhaps “tattooed” DNA vaccines will never be a mainstream option, but for people who are already in excruciating pain, they are a life-changing alternative. Hopefully in twenty years or so many more people will be under the needle for the sake of health, not just art.