Generation of tumor-specific T lymphocytes for the treatment of posttransplant lymphoma.
BACKGROUND
The incidence of lymphoproliferative disease, including B-cell lymphomas (BCL) in patients who have undergone heart or combined heart-lung transplants, has been reported to be as high as 15%. The majority of these tumors contain Epstein-Barr virus (EBV) DNA and regress when immunosuppressive agents are discontinued. This tumor regression is thought to be secondary to cytotoxic T lymphocytes (CTL) reactive to EBV-infected cells whose function is impaired in patients receiving immunosuppressive agents. We hypothesize that EBV-CTL expanded in the absence of these agents may demonstrate an antitumor effect against an EBV-expressing human BCL in vitro and in vivo.


RESULTS
An EBV-expressing BCL from a heart transplant recipient was isolated and expanded in culture. EBV-CTL were generated by stimulation of peripheral blood leukocytes with irradiated autologous tumor cells in low-dose interleukin-2. Autologous BCL, HLA-mismatched BCL, lymphokine-activated killer target cell line (Daudi), and the natural killer target cell line (K562) were used in a standard 4-hour cytotoxicity assay using 51CrO4 after 7, 14, and 28 days of stimulation. There was significant percent specific lysis of autologous BCL targets (78%) at an effector-to-target ratio as low as 20:1 as compared with control cells. EBV-CTL were then adoptively transferred into SCID mice (provided by Duke University Vivarium) that had been engrafted with autologous BCL 7 days before. There was a significant survival advantage to those mice engrafted with EBV-CTL as compared with control cells.


CONCLUSIONS
The results indicate that ex vivo expansion of EBV-CTL in the absence of immunosuppressive agents results in a population that has significant antitumor activity. This strategy may be useful in the generation of EBV-CTL that might be effective antitumor agents in transplant recipients with EBV-associated lymphomas.
DiMaio
J M
JM
Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA.
Van Trigt
P
P
Gaynor
J W
JW
Davis
R D
RD
Coveney
E
E
Clary
B M
BM
Lyerly
H K
HK
D000818:Animals; D002460:Cell Line; D002469:Cell Separation; D003601:Cytotoxicity Tests, Immunologic; D005434:Flow Cytometry; D016027:Heart Transplantation; D004854:Herpesvirus 4, Human / Q000302:isolation & purification; D006801:Humans; D016219:Immunotherapy, Adoptive; D016393:Lymphoma, B-Cell / Q000473:pathology / Q000628:therapy* / Q000821:virology; D051379:Mice; D016513:Mice, SCID; D011183:Postoperative Complications / Q000628:therapy*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000637:transplantation*