Human immune cells grown in pigs

摘要

Individual "piggy banks" of immune cells might one day be used to boost our own immune systems or to fight HIV and cancer. The immune cells would be grown in piglets from each patient's own cells. Our immune system's T-cells, which play a key role in fighting off diseases, are "primed" in childhood to fight particular pathogens. This plasticity diminishes after puberty, but Jeffrey Platt at the University of Michigan, Ann Arbor, has come up with a way to revive it. He reckons that if a human's immune cells are transferred into a young pig, they could become primed like a child's, then implanted back into the person they came from. To see if growing a human immune system inside pigs is possible, Platt and his colleagues extracted stem cells from human umbilical cord blood and bone marrow, and injected them into developing pig fetuses. Lacking a mature immune system, the fetuses accepted the foreign tissue as their own, and when the piglets were born Platt found that the injected cells had multiplied and matured into a diverse range of human T-cells, alongside the pig's own immune cells. The researchers separated out the human T-cells from the pig's blood and mixed some of them with ordinary cells from the person whose cells had been injected into the fetus.