MIT researchers have devised a new technology that they say may make it easier to develop HIV vaccines.

The technology measures various aspects of responses of individual T cells to HIV-infected cells. It has been a challenge to develop an effective AIDS vaccine because it is difficult to measure how well the vaccine candidate primes the body to defend itself against HIV, according to an MIT news report.

The MIT technology involves first placing single T cells from HIV-infected patients into tiny wells on a plate, where they are exposed to HIV-infected cells. The researchers can detect whether the T cells kill the infected cells using probes that glow. The second step is to measure interferon gamma production with a microengraving technique the MIT researchers developed in 2008. Cell secretions imprinted on a glass slide can then be tested for the presence of specific proteins. Because each cell has its own “address” on the slide, the secretions can be traced back to individual cells, and their interferon gamma production can be correlated directly to their cell-killing ability.

The microengraving technique was developed by MIT chemist J. Christopher Love and his colleagues. The researchers described the potential vaccine technology in the Oct. 3 online edition of the Journal of Clinical Investigation. At the end of the paper, Love disclosed a conflict of interest as the founder of and consultant with Enumeral Biomedical Corp. of New York, which makes the microengraving technology he helped develop and that was used in the MIT experiments. Enumeral in May closed on $2 million of a planned $3.34 million offering.

“The appeal of this technology is that it can help us understand more about what’s going on in single cells,” Alan Landay, professor of immunology and microbiology at Rush Medical College, said in a statement. “It helps us rethink what we understand about immunology and immune function.”
Love said that now that they have a tool to look directly at a variety of different functional activities, it is possible to start evaluating other markers that may better predict killing. “Those then become what you would want to monitor in vaccine trials,” Love said.

In their study, the researchers found that while the percentage of T cells that secrete interferon gamma is similar to the percentage of those that kill infected cells, the populations are not identical. In future studies, they hope to find markers that correlate with cell-killing ability, making it easier to evaluate a potential vaccine’s effectiveness.

The same technology could be adapted to the cell’s output of other immune system proteins. The scientists said more research will be needed to develop the technology to where it can be used in vaccine trials.