B cells are workhorses of the immune system. Their main function is to produce antibodies against bacteria or viruses when they encounter something that they recognize.Â But recently researchers have been getting hints that certain kinds of B cells can also have a calming effect on the immune system. This property could come in handy with hard-to-treat conditions such as graft-vs-host disease, multiple sclerosis, or Crohn’s disease.
Hematologist Jacques Galipeau has found that B cells treated with an artificial hybrid molecule called GIFT15 turn into “peacemakers”. These specially treated B cells can tamp down the immune system in an experimental animal model of multiple sclerosis, suggesting that they could accomplish a similar task with the human disease.
Galipeau’s paper inÂ Nature Medicine from August 2009 says succinctly: “We propose that autologous GIFT15 B regulatory cells may serve as a new treatment for autoimmune ailments.”Â Galipeau, a recent arrival to Emory from McGill University in Montreal, explains this tactic and other aspects of personalized cell therapy in the video above.
Unexpectedly, a group of transplant specialists has discovered that B cells may also play a role in long-term tolerance of a transplanted organ. Ken Newell at Emory Transplant Center and several colleagues at the Immune Tolerance Network were studying rare individuals who were able to wean themselves completely off the immunosuppressive drugs that most kidney transplant recipients need to take. (Don’t try this at home! – most people who try this don’t succeed and it can result in immune rejection of the transplanted organ.)
Scanning the pattern of genes turned on in their immune cells to see what makes these people different, Newell’s team zeroed in on their B cells. The results suggest that regulatory B cells may be preventing the transplant recipients’ immune systems from going off the rails, Newell told Science News.
He says that these results could be used to devise a pattern of genes to look for in kidney transplant recipients, to predict whether they might be able to reduce the immunosuppressive drugs they take. Because of the risks involved, careful studies are needed to see if this could work as a deliberate strategy.