University of Washington scientist Dr. David Baker, a renowned expert in the design of arificial proteins, discussed how these laboratory-created nanoparticles might be used in gene therapy to cure HIV.

Closer on the horizon are technologies that package HIV-fighting genes within the protein shells of viruses, which take advantage of nature’s preferred method of slipping foreign DNA in a cell’s genetic machinery. In numerous presentations, a family known as adeno-associated viruses, or AAVs, emerged as the most-favored vehicles, and researchers are busy reengineering these particles to make them more efficient at carrying their cargo, delivering it to the right places and less likely to provoke a patient’s immune system to attack them.

“You have to tailor and optimize,” said Dr. Hildegard Büning, from Hannover Medical School in Germany. “We have to teach the viral vector to do its job.”

AAVs are harmless viruses, but researchers are also looking at using stripped down versions of nastier bugs, such as Nipah and measles viruses, as vehicles for delivering therapeutic molecules instead of diseases.

University of Washington researcher Dr. André Lieber showed an alternative approach using adenovirus, which causes cold-like symptoms in people. Using only the shell of the virus as a container — the microbe emptied of its genes — he is able in preclinical studies to transport genes to immune cells in the body and treat blood cell disorders and cancer. These modified viruses can be freeze-dried and shipped, and they have another advantage: lower cost.

“It is very simple to make these vectors,” Lieber said. “The procedure takes six hours, and the cost per patient based on my lab estimates would be about $3,000.”

During the two-day conference, scientists presented their work on a wide variety of strategies to identify and destroy latent reservoirs of HIV — a problem identified more than two decades ago by the Johns Hopkins University lab of Dr. Robert Siliciano, the event's keynote speaker. They include continued work to make transplantation of HIV-resistance genes simpler and safer, and explorations of different techniques to edit the genes of immune cells to make them resistant to HIV.

T-cell therapy, in which immune cells from a patient are selected or genetically reprogrammed to target cancer, is being explored as a technique to target reservoirs of latent HIV. Fred Hutch immunotherapy scientist Dr. Aude Chapuis noted that she began her career as an HIV scientist exploring ways to get T cells to target cells infected with HIV. It didn’t work, but she described how her current work in fine-tuning T cells as “serial killers” of Merkel cell carcinoma might inform the latest research in coaxing such cells to target HIV. “It’s nice to see that things are coming back,” she said.

Among the challenges facing HIV cure research is how to recruit volunteers for the essential early trials of these gene therapies, which may rival in complexity to transplant treatments for cancer. Given the control of the virus afforded by antiviral drugs, potential participants must weigh the risks and benefits of joining a trial. Laurie Sylla, a member of the defeatHIV community advisory board, discussed a Seattle focus-group study that found considerable wariness on the part of potential patients.

“People were afraid to change what they felt was already working for them,” she said. Another focus group comment she related was, “Give it to Magic Johnson, and then we’ll see how I feel about it.”