Science Daily (10.21.2013)
Aids Weekly Plus
Researchers at North Carolina’s Duke University School of Medicine reported that they have found a protein in breast milk that has antimicrobial properties that kill infections, including HIV. The protein, called Tenascin-C or TNC, was previously known to have healing properties.
The researchers used mature milk samples from uninfected women to investigate the HIV neutralization activity. They separated the proteins and were able to identify the TNC protein. Additional studies helped them determine how TNC blocks the virus by capturing and neutralizing virus particles. According to Sallie Permar MD, PhD, assistant professor of pediatrics, immunology and molecular genetics and microbiology at Duke, and the study’s senior author, “TNC is a component of the extracellular matrix that is integral to how tissues hold themselves together.” She explained that TNC is involved during wound healing and has a role in tissue repair and fetal development. Permar stated that TNC might be acting with other anti-HIV factors in breast milk, but further research would be needed to prove this.
Also, Barton F. Haynes, MD, director of the Duke Human Vaccine Institute, commented that this discovery might explain why more nursing infants born to HIV-infected women do not become infected.
Since TNC is a found naturally in breast milk, the researchers believe that it could be used to develop an oral prevention therapy because it is safe and might prevent HIV resistance to antiretrovirals. They also surmise that introducing inhibitory factors in breast milk, such as antibodies, might make it more protective thus completely preventing HIV in babies.
The full report, “Tenascin-C Is an Innate Broad-Spectrum, HIV-1–Neutralizing Protein in Breast Milk,” was published online in the journal Proceedings of the National Academy of Sciences (2013; doi: 10.1073/pnas.1307336110).