New study brings insight on “cured” AIDS patient

Timothy Ray Brown is the only human cured of HIV. He had lived with the HIV for elven years, when he was diagnosed with acute myeloid leukemia. When chemotherapy failed to cure him, he stopped taking his antivirals for HV and received two bone marrow transplants. Eight years later, only tiny traces or HIV (which are unable to replicate) have been found in Timothy Ray Brown’s blood.

There are three factors possible hypothesizes for this result. The first being is the immune conditioning provided by Brown’s earlier chemotherapy allowed for the result. The second is the fact that the donator of the bone marrow had a rare mutation in the CCR5 (one of the two receptors, as well as CD4 that allows HIV to infect cells) gene known as δ32, which prevents HIV from infecting cells. The third is graft vs. host disease—the immune factors of the new, transplanted immune system attacked the old immune system.

A new study from Emory University tests these hypothesizes. Rhesus monkeys and SHIV (Simian-Human immunodeficiency virus, which contains elements of both viruses) were irradiated to kill 94-99% of CD4+ T-cells. The monkeys received transplants of their own bone marrow and soon had elevated levels of SHIV cells, proving that immune conditioning alone is not enough to cure the aids virus and eliminate the marrow virus reservoir. While Brown’s treatment may show potential, there is a while to go before it can be utilized on a wider scale.

By Madeleine Bousquet

Sources:

https://www.sciencemag.org/content/332/6031/784.full

http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1004406