Methods for generating highly enriched Th1/Tc1 and Th2/Tc2 functions are described. In particular, the generation of these functions are attained by the addition of an immune suppression drug, rapamycin or a rapamycin derivative compound. In addition to enhanced purity of T cell function, the T cells generated in rapamycin also express molecules that improve immune T cell function such as CD28 and CD62L. Such rapamycin generated functional T cell subsets may have application in the prevention or treatment of GVHD after allogeneic hematopoietic stem cell transplantation, the treatment of autoimmunity, or the therapy of infection or cancer.