New research shows that a protein in breast milk protects against HIV. While it is know that breast milk of untreated mothers with HIV can infect some infants, it was not understood why it was such a low rate. Turns out that a protein, tenascin-C, in breast milk attaches itself to HIV, thus disabling it.
Genevieve Fouda of Duke University and her fellow researchers say that tenascin-C naturally protects infants from contracting HIV. Their research was published recently in the Proceedings of the National Academy of Sciences. As The Economist points out, the news is important because it shows one way that HIV can be rendered ineffective.
This was a surprise, because tenascin-C is not an antibody, nor had it been suspected of having any antiviral function. Its known jobs are to help the development of the fetal brain and to assist in wound healing. That it is also the right shape to attach itself to HIV’s envelope protein seems a complete coincidence—which, indeed, it must be because AIDS is such a recent disease that evolution could not have had time to throw up a novel (and also ubiquitous) anti-HIV protein of this sort.
Whether tenascin-C, or something derived from it, can be deployed against HIV by doctors, rather than just by nature, remains to be seen. As far as possible, infected mothers are now given antiretroviral drugs—both for their own health and for the health of their suckling infants—so Dr Fouda’s discovery will probably not affect them directly.
Using the protein will be a big challenge, but knowing what is effective against HIV brings the world closer defeating the virus.