Todd Allen, PhD, of the Ragon Institute of MGH, MIT and Harvard, in collaboration with Andrew Tager, MD, of Mass General, made one of the most important discoveries to come out of the institute in the past year. They created a better mouse model for HIV vaccine testing.
“Animal models accelerate biomedical research exponentially because research can move faster than in humans,” Dr. Allen says. “For HIV, we really need a model that mimics how a human immune response recognizes the virus and how the virus then adapts.”
Dr. Allen and his team reconstituted a human immune system in a mouse model by implanting human cells from bone marrow, the liver and thymus. After infecting these mice with HIV, the mice mounted the same immune responses to HIV as humans. Surprisingly, using gene sequencing, researchers found that HIV in these mice could also mutate to escape immune responses, as HIV does in human patients taking antiretroviral drugs.
And, they discovered the model could also mimic immune responses of a protective human gene known to control HIV in a small portion of the human population — a group called HIV elite controllers — by keeping viral loads low enough to prevent them from progressing to AIDS.
The model now gives researchers a place to more rapidly test HIV vaccines that could help prevent new infections and the spread of the virus from person to person. The past two years have brought hopeful news as understanding of HIV vaccines and therapies has advanced, Dr. Allen says. “I think we’re seeing a new dawn of enthusiasm for HIV vaccines, and we expect our new model to help accelerate these studies,” he adds.