Prior to transplantation, patients will undergo diphtheria/tetanus (DT) vaccination and blood collection. Two weeks after vaccination, patients will have a Hickman catheter inserted into their bodies and will be admitted to the hospital to receive mobilization chemotherapy with intravenous (IV) cyclophosphamide. Patients will be discharged after receiving the cyclophosphamide therapy with the understanding that they must stay locally and must return to the outpatient clinic daily to have blood samples drawn and to receive an injection of a growth factor, G-CSF, in stimulate blood cell production. Patients will undergo leukapheresis at the clinic when their white blood cell (WBC) counts reach 2500 cells/mm3 or more. A machine called the Nexell Isolex 300i will be used to remove T-cells from the cells collected by leukapheresis.