The T cell is one of two main classes of lymphocytes (a type of white blood cell), which play a role in the bodys immune system. Scientists have long believed that T cells rely on the spleen and lymph nodes to mount an immune response against toxins, bacteria and the foreign blood cells of a transplant. In the new study, investigators discovered that memory T cells, unlike nave (resting) T cells, can trigger the rejection of a transplant even when the spleen and lymph nodes are removed.
Fady Baddoura, M.D., of the Buffalo VA Medical Center, developed a new method for staining and visually tracking memory T cells to follow their actions in the tissue of transplanted hearts in mice. The mice used in the study had their spleen and lymph nodes removed, thus disabling other types of T cells, such as killer T cells. But the animals memory T cells were still able to react and reproduce on their own, mounting an attack against the transplanted hearts.
The tissue staining method "provides reliable visual proof of the presence, location and intensity of the T cells responsible for rejection," said Dr. Baddoura. "Future studies will use this method to further analyze how memory T cells act against transplanted tissue, and identify new compounds that may block this rejection function."
The research team believes the findings may help improve the success rate of organ transplants in the future. "Despite improvement in short-term outcomes, most tran
Contact: Arlene Kelly
VA Research Communications Service