By analyzing tissues harvested from organ donors, Columbia University Medical Center (CUMC) researchers have created the first ever "atlas" of immune cells in the human body. Their results provide a unique view of the distribution and function of T lymphocytes in healthy individuals. In addition, the findings represent a major step toward development of new strategies for creating vaccines and immunotherapies. The study was published today in the online edition of the journal Immunity.
T cells, a type of white blood cell, play a major role in cell-mediated immunity, in which the immune system produces various types of cells to defend the body against pathogens, cancer cells, and foreign substances.
"We found that T cells are highly compartmentalized — that is, each tissue we examined had its own complement of T cells," said study leader Donna L. Farber, PhD, professor of surgical sciences at CUMC and a principal investigator with the new Columbia Center for Translational Immunology (CCTI), directed by Megan Sykes, MD. "The results were remarkably similar in all donors, even though these people were very different in terms of age, background, and lifestyle."
The researchers also discovered a receptor that is expressed on the surface of "tissue-resident" T cells but not on circulating T cells. Using this marker, Dr. Farber and her colleagues established that the blood is its own compartment. "In other words, T cells found in circulation are not the same as T cells in the tissues," said Dr. Farber.