Alfred Singer (born December 10, 1946) is an American immunologist who works at the National Institutes of Health (NIH), where he is the Chief of the Experimental Immunology Branch of the National Cancer Institute (NCI) Center for Cancer Research.[1] He is best known for his work regarding lymphocyte development, particularly the differentiation of immature CD4+8+ (double positive) thymocytes into mature T cells. Singer's work is foundational in the understanding of T cells and MHC-restricted antigen recognition.[2]
Singer's work explores the mechanisms with which a body identifies what is self and what is not self. At a time when many researchers understood that T cells recognize self through identification of the major histocompatibility complex (MHC) it was not understood how T cells acquire that capability. Using a unique approach to thymus transplantation, Singer showed that it is the thymus that educates self-recognition specificity in T cells.[3] A series of later studies in Singer's lab demonstrated that the property of self-recognition in T cells is acquired during development in the thymus rather than predetermined prior to development or genetically encoded in the genome.[4]
Singer was raised in Port Jervis, New York, the eldest son of a baker. He studied philosophy at the Massachusetts Institute of Technology, where he received his BS in 1968 and met his wife, Dinah Singer. He received his MD from the Columbia University College of Physicians & Surgeons and was a fellow in immunology at the Rockefeller University before joining the NCI as a clinical associate in the Immunology Branch in 1975. In 1982, Singer established the Experimental Immunology Branch, of which he remained the branch chief.[1]