Abstract: Cell preparations comprising a plurality of apoptotic EBV-transformed B lymphocytes, and methods of producing cell preparations comprising a plurality of apoptotic EBV-transformed B lymphocytes are provided. The methods comprise transforming B lymphocytes with EBV, incubating the transformed B lymphocytes with a flavin photosensitizer, such as riboflavin or a lumichrome-resistant photosenstizer, adding a non-toxic anti-oxidant, and exposing the lymphocytes to photoradiation of an appropriate wavelength to activate the photosensitizer. Also provided are methods of using the apoptotic EBV-transformed B lymphocyte cell preparations to elicit production of EBV-specific T cells in human patients. Finally, methods of treating organ transplant patients comprising administering an effective amount of the apoptotic EBV-transformed B-lymphocytes cell preparation to the patients prior to transplantation are provided.