7 February 2008

Ink Delivers DNA

by Kate Melville

The journal Genetic Vaccines and Therapy reports that German researchers have found tattooing to be an extremely effective method for delivering DNA vaccines. "Vaccination with naked DNA has been hampered by its low efficiency," said Martin M�ller, of the German Cancer Research Center. "Delivery of DNA via tattooing could be a way for a more widespread commercial application of DNA vaccines."

Using a coat protein from the human papillomavirus as a model DNA vaccine antigen, they compared delivery by tattooing the skin of mice against standard intramuscular injection with, and without, the molecular adjuvants that are often given to boost immune response.

M�ller found that the tattoo method gave a stronger humoral (antibody) response and cellular response than intramuscular injection, even when adjuvants were included in the latter. Three doses of DNA vaccine given by tattooing produced at least 16 times higher antibody levels than three intramuscular injections with adjuvant. The adjuvants enhanced the effect of intramuscular injection, but not of tattooing.

M�ller explained that tattooing provokes inflammation which "primes" the immune system. Additionally, tattooing covers a bigger area of the skin than an injection, so the DNA vaccine can enter more cells. M�ller speculates that these effects may account for the stronger immune response. The researchers believe that tattooing could play a role in the routine vaccination of cattle or in delivering therapeutic vaccines to humans.

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Source: BioMed Central