We knew from previous studies that breast milk was able to block the HIV virus under laboratory conditions, but researchers at the Duke University, in Durham, United States, have identified a substance in Breast milk that could protect the baby from HIV infection through their infected mothers by neutralizing the virus.
A protein called tenascin-C
Also known by TNC, it is an old woman known to researchers because of its role in tissue healing, although it was not known to have antimicrobial properties.
The discovery, published Monday in Proceedings of the National Academy of Sciences, could open the door to new HIV prevention strategies. In the article, the researchers describe how the TNC protein in breast milk binds and neutralizes the HIV virus, which could protect exposed infants who might otherwise be infected by repeated exposures to the virus.
There are antiviral treatments that prevent mother-child infection, but not all mothers know whether or not they have the virus and in developing countries access to treatments is complicated.
According UNICEF, in 2011 a total of 330,000 children contracted HIV from their mothers during pregnancy or childbirth or through breastfeeding. With this discovery this figure could be reduced.
Permar and his colleagues they knew that breast milk had antiviral properties, but the mechanism that made it possible was unknown, so the team focused on that.
In their study, Duke's team examined samples of mature milk from uninfected women to neutralize activity against a panel of HIV strains, confirming that all of the detectable HIV neutralization activity was in the high molecular weight part (which generally corresponds to proteins). By using a multi-step protein separation process, the researchers reduced the activity of neutralizing detectable HIV to a single protein, which they identified as TNC.
"TNC is a component of the extracellular matrix that is an integral part of the way in which tissues are held together. It is a protein involved in wound healing, which plays a role in tissue repair. It is also known by be important in the development of the fetus but it had never been described as a component of breast milk or for its antiviral properties, "said Permar.
This expert said that due to the broad spectrum activity of TNC, binding and neutralization of HIV-1, It could be developed as an HIV prevention therapy, administered orally to children before breastfeeding, similar to oral rehydration that is routinely administered to newborns in developing regions.
Permar added that the TNC also seems to be inherently safe, as It is a natural component of breast milk and can avoid the problem of HIV resistance to antiretroviral regimens.
