Immunologists refer to the cells that harbor HIV, even while someone is getting effective antiretroviral drugs, as the “reservoir.” That term inspires a lot of waterway metaphors! Unfortunately, drying up the HIV reservoir is not as straightforward as building a dam across a stream. But it is the goal, if we are talking about the still-elusive possibility of a HIV cure.
Maud Mavigner, Ann Chahroudi and colleagues at Yerkes recently published a paper in Journal of Virology on targeting the Wnt/beta-catenin pathway as a tactic. They were studying SIV-infected macaques, in the context of ongoing antiretroviral therapy.
The HIV reservoir is more difficult to visualize than a human-made aquatic reservoir
Wnt is one of those funky developmental signaling pathways that gets re-used over and over again, whether it’s in the early embryo,the brain or the intestine. Beta-catenin is a central protein in that pathway.
In this case, Wnt/beta-catenin regulates the balance between self-renewal and differentiation of memory T cells – important components of the HIV reservoir. Mavigner’s team used PRI-724, a molecule that blocks interaction between beta-catenin and another protein it needs to turn on genes. PRI-724 has also been investigated in the context of cancer clinical trials. Read more
Stem cell researchers at Emory University School of Medicine have made an advance toward having a long-lasting “repair caulk” for blood vessels. The research could form the basis of a treatment for peripheral artery disease, derived from a patient’s own cells. Their results were recently published in the journal Circulation.
A team led by Young-sup Yoon, MD, PhD developed a new method for generating endothelial cells, which make up the lining of blood vessels, from human induced pluripotent stem cells.. When endothelial cells are surrounded by a supportive gel and implanted into mice with damaged blood vessels, they become part of the animals’ blood vessels, surviving for more than 10 months.
“We tried several different gels before finding the best one,” Yoon says. “This is the part that is my dream come true: the endothelial cells are really contributing to endogenous vessels. When I’ve shown these results to people in the field, they say ‘Wow.'”
Previous attempts to achieve the same effect elsewhere had implanted cells lasting only a few days to weeks, although those studies mostly used adult stem cells, such as mesenchymal stem cells or endothelial progenitor cells, he says.
“When cells are implanted on their own, many of them die quickly, and the main therapeutic benefits are from growth factors they secrete,” he adds. “When these endothelial cells are delivered in a gel, they are protected. It takes several weeks for most of them to migrate to vessels and incorporate into them.” Read more