Circulation. 1995;92:202-205
(Circulation. 1995;92:202-205.)
© 1995 American Heart Association, Inc.
Generation of Tumor-Specific T Lymphocytes for the Treatment of Posttransplant Lymphoma
J. Michael DiMaio, MD;
Peter Van Trigt, MD;
J. William Gaynor, MD;
R. Duane Davis, MD;
Eamonn Coveney, MD, FRCSI;
Bryan M. Clary, MD;
H. Kim Lyerly, MD
From the Departments of Surgery (J.M.DiM., P.V.T., J.W.G., R.D.D., E.C.,
B.M.C., H.K.L.) and Pathology (H.K.L.), Duke University Medical Center,
Durham, NC.
 |
Abstract
|
|---|
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.
Methods and 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.
Key Words: lymphocytes transplantation cells heart transplant lymphoma immunodeficiency
 |
Introduction
|
|---|
The incidence of
lymphoproliferative disease, including BCLs
in patients who have
undergone heart or combined heart-lung
transplants, has been
reported to be as high as 15%. The mortality
associated with these
tumors that appear more than 1 year posttransplant
is approximately
70%. The majority of these BCLs contain EBV
DNA as demonstrated by DNA
hybridization studies, polymerase
chain reaction, and
immunohistochemistry.
1 2 3
As many as 89% of these tumors regress in thoracic organ
transplant patients when immunosuppression is discontinued if the tumor
appeared within the first year of
transplantation.4 5 6 This
phenomenon is thought to be the result of the repopulation of EBV-CTL,
which are suppressed by cytotoxic agents such as
cyclosporine. Therefore, it is hypothesized that autologous
EBV-CTL expanded in the absence of these immunosuppressive agents may
demonstrate an antitumor effect against an autologous EBV-expressing
human BCL in vitro and in vivo.
 |
Methods
|
|---|
Isolation of Posttransplant Lymphoma and Human Cell Lines
After informed consent was obtained a tumor was obtained from
a
patient who had developed a BCL 7 years after an orthotopic
heart
transplant for ischemic cardiomyopathy. The tumor was
minced
and passaged. At surgery, portions of excised tumor were
placed in
either sterile saline, snap-frozen in liquid nitrogen,
or fixed in
neutral-buffered formalin. Those portions in saline
were
mechanically dispersed into single-cell suspensions and
layered and
placed in culture in 25-cm
2 flasks (CoStar) with
RPMI 1640
(Sigma Chemical Co)/20% FCS with supplemental antibiotics.
BJAB is an
ATCC (American Type Culture Collection, Rockville,
Md) line isolated
from human Burkitt's lymphoma that is EBV
negative.
FACS Analysis
FACS was performed by single- or
double-staining of isolated
cells by direct techniques using phycoerythrin- or
fluorescein isothiocyanateconjugated monoclonal
antibodies. Cells were washed with cold PBS containing 0.5% BSA and
0.1% NaN3. The cells were then incubated with directly
labeled antibodies for 30 minutes at 4°C. The cells were washed and
analyzed in an EPICS C flow cytometer (Coulter) at 488 nm for
percent positivity on a log fluorescent scale. Background
control tubes were incubated with directly labeled class-matched
mouse Igs. Monoclonal antibodies CD4 (OKT4), CD8 (OKT8), and CD19
(OKB-PanB) from Ortho Diagnostics and CD3 (Leu-4), CD19
(Leu-12), CD20 (Leu-16), CD22 (Leu-14), CD23 (Leu-20), and CD56
(Leu-19) from Becton-Dickinson were used for single and dual
color-flow cytometry.
SCID Mice
SCID mice were obtained from a
hysterectomy-rederived
central inbred colony of defined flora-gnotobiotic stock maintained
at Duke University. After transfer to a biosafety level 3 isolation
facility, mice were maintained in filter-capped Micro-Isolator
cages (Lab Products Inc). Cages were housed within a HEPA-filtered
Blickman isolator system (Blickman), and mice were fed sterilized
rodent chow. Before all manipulations, Micro-Isolator cages were
transferred to a laminar flow Bioguard hood (The Baker Co), and animals
were handled aseptically by investigators wearing sterile gloves,
masks, and gowns. Blood samples were obtained from all mice before
their induction into experiments by retroorbital sinus bleeding. Serum
from mice was screened for murine Ig by ELISA and total murine Ig
levels were quantified using goat antimouse Ig. Mice with Ig levels
greater than 0.01 mg/mL, indicative of leakiness of the SCID defect,
were excluded from study.
Histopathology
The primary human tumor and SCID mice tumors
were processed
simultaneously. Formalin-fixed specimens were
dehydrated and embedded in paraffin, and 5-µm sections were cut and
stained with hematoxylin and eosin for morphological evaluation.
Immunohistochemistry
Frozen sections (5 µm) prepared in
the usual fashion were
stained by an avidin-biotin procedure with a panel of monoclonal
antibodies including CD20 (L26, B cell antigen; Dako), CD3 (pan-T cell
antigen; Becton-Dickinson), and CD45 RO (UCHL-1, pan leukocyte antigen;
Dako).
Frozen sections were also stained with antibodies to EBNA 2
(EBV-encoded nuclear antigen 2) and LMP-1 (EBV-encoded latent membrane
protein) from Dako Corp.
Both frozen and paraffin sections were stained
with polyclonal rabbit
antihuman to kappa and lambda Ig light chain (Calbiochem-Behring Corp)
for determination of clonality.
In Situ Hybridization
A biotinylated probe for EBV-DNA
(Epstein-Barr virus
Bioprobe-labeled probe; Enzo Diagnostics) was used for
the detection of EBV genomes in formalin-fixed sections.
Generation of AntiEBV CTL
Peripheral blood from the
patient was diluted 1:3
with PBS and layered over a Ficoll-Hypaque gradient. The mononuclear
cell layer was then washed twice and cocultivated with
gamma-irradiated BCL in AIM-V media with 5%
heat-inactivated autologous plasma for 7 days at a
concentration of 1x106 cell/mL with a
responder-to-stimulator ratio of 5:1. Repeated
stimulations of EBV-CTL were performed at days 7 and 21 with irradiated
BCL and a similar responder-to-stimulator ratio. After the
second stimulation, recombinant interleukin-2 (rIL-2); 10 IU/mL,
Chiron) was added, and the cells were counted and expanded every 3 days
with the addition of fresh rIL-2.
Cytotoxicity Assay
Target cells were incubated with
51CrO4
washed, resuspended at 5x104 cells/mL, and combined in
triplicate wells of 98-well round-bottom plates with effector cells
for E-T (effector to target) ratios of varying numbers. Final volumes
of each well were adjusted to 0.2 mL with AIM-V media. Wells containing
only culture media and target cells or 5% triton and target cells
served as spontaneous and maximum 51Cr release controls,
respectively. The plates were incubated at 37°C in 5%
CO2 for 4 hours; then 0.10 mL of medium from each well was
removed for counting in a Packard Prias gamma spectrometer. Percent
specific lysis was calculated by standard methods.
Tumor Cell Engraftment and Development
A reliable and
reproducible model of human B-cell tumors
(SCID-BCL) in SCID mice has been developed in this laboratory. After
engraftment with PBL (peripheral blood leukocytes), engraftment with
PBL followed by inoculation with EBV, and engraftment of LCL
(lymphoblastoid cell line) results in the development of B cell tumors.
To test the effect of adoptive transfer of EBV-CTL on SCID/BCL
development 25x106 EBV-CTL were inoculated into the
peritoneal cavity of SCID mice 7 days after IP inoculation of
5x106 tumor cells or Dulbecco's PBS (Gibco). Mice
were monitored twice weekly, weight and examination for tumor
development. Mice were anesthetized with halothane (Fluothane;
Ayerst), killed by cardiac puncture, and autopsied. At autopsy,
thoracic and abdominal cavities were examined, and tumors were
sectioned and cryopreserved in liquid nitrogen or fixed in 10%
neutral-buffered formalin. All procedures were approved and
conducted in accordance with institutional guidelines.
 |
Results
|
|---|
Pathology
The patient's primary tumor and those that
developed in the
SCID
mice were polyclonal B-cell type as shown in Fig 1

. The
presence
of EBV was confirmed in the primary patient's tumor and the
SCID
mice by in situ hybridization as seen in Fig 2

.
FACS analysis
revealed significant staining of the tumor cells
with B-cell
markers CD 19 (95%) and 20 (84%) as well as the EBV
receptor
CD21 (92%). The EBV viral products EBNA 2 and LMP were
noted
by immunohistochemistry.

View larger version (0K):
[in this window]
[in a new window]
|
Figure 1. Representative hematoxylin and eosin
stain of EBV expressing posttransplant B-cell lymphoma. (magnification
x100; inset, x10.)
|
|

View larger version (0K):
[in this window]
[in a new window]
|
Figure 2. Representative EBV in situ
hybridization stain of EBV-expressing posttransplant B-cell lymphoma
from patient or engrafted into SCID mice. (magnification
x100.)
|
|
FACS Analysis
As shown in the Table
, the
EBV-CTL generated
progressed to 97% CD3+ (pan-T cell) and 88% CD8+ (cytotoxic T cell)
after 28 days of stimulation. The majority of CD8+ cells were positive
for S6F1 (cytotoxic T cell). The population of B cells or natural
killer (NK) target cells diminished with time, to near zero.
Cytotoxicity Assay
Effective cytolysis of the autologous
targets was demonstrated by
EBV-CTL 7, 14, and 21 days after stimulation as seen in Fig 3
.
No cytolysis of HLA-mismatched EBV-expressing cell
lines was seen. Minimal cytolysis of the NK target K562 was seen on day
7, which diminished by day 14. There was no activity against LAK
(lymphokine activated killer) cell target Daudi (data not shown).

View larger version (27K):
[in this window]
[in a new window]
|
Figure 3. Cytotoxicity assay of anti-EBV CTL 7 (A), 14 (B),
and 21 (C) days after stimulation with autologous lymphoma cells.
Percent specific lysis at various effector-target ratios for
EBV-specific CD8+CTL against autologous posttransplant lymphoma cells
(autologous), EBV-positive HLA-unmatched cells (HLA mismatched), and a
natural killer target cell, K562 (NK).
|
|
Adoptive Transfer of EBV-CTL
Results of SCID-BCL and BJAB-BL
engraftment and survival as well
as the inoculation of EBV-CTL are shown in Fig 4
.
Engraftment of posttransplant B-cell lymphoma and Burkitt's lymphoma
led to the characteristic tumor development and death of the animals in
50 days. Animals inoculated with EBV-CTL 7 days after engraftment
with the EBV-negative cell line BJAB (Burkitt's lymphoma) showed no
significant difference in survival from the animals engrafted with
tumor and then given PBS (P=NS via log rank test). In
contrast, animals given autologous EBV-CTL 7 days after engraftment of
EBV-expressing BCL had no deaths (P<.05 via log rank
test).

View larger version (16K):
[in this window]
[in a new window]
|
Figure 4. A, Kaplan-Meier survival curves of SCID
mice engrafted with EBV-expressing posttransplant B-cell lymphoma (Post
Tx-BCL) and PBS compared with EBV-expressing posttransplant B-cell
lymphoma followed by autologous EBV-specific cytotoxic T lymphocytes
(Post-Tx BCL+CTL). There was a significant difference
(P<.05) as determined by the log rank test. B,
Kaplan-Meier survival curves of SCID mice engrafted with EBV-negative
B-cell Burkitt's lymphoma (BJAB-BL) and PBS compared with EBV-negative
Burkitt's B-cell lymphoma followed by EBV-specific cytotoxic T
lymphocytes (-BJAB-BL+CTL). There was no significance difference
(P=NS) as determined by the log rank test.
|
|
 |
Discussion
|
|---|
Cell-mediated immune responses to EBV infection are considered
to
be more crucial to the outcome of infection than the humoral
responses.
A lymphocytosis is composed primarily of CD3+/CD8+ T
lymphocytes
and is usually seen in acute EBV infection. This early
response
appears to be a polyclonal T cell activation. Two to 8 weeks
after
active EBV infection, a more EBV-specific T-cell response can
be
seen by in vitro proliferation to viral antigen and EBV-specific
HLA-restricted
lysis of EBV-infected B
cells.
7 8 9 EBV-CTLs
have been cloned
from the blood of EBV seropositive donors and inhibit
cytotoxicity
that is highly specific for EBV-infected cells and are HLA
restricted.
10 11
Wherever productively infected cells are cleared by the immune
system, latently infected B cells persist for the life of the host. In
fact, B cells infected with EBV become immortalized B-cell lines and
provide a model system of EBV latency.12 13
Evidence suggests that cellular immune response may be effective in
controlling EBV-associated LPDs and BCLs in patients who have undergone
transplantation.14 15 The term LPD applies to the
development of continuously proliferating B lymphocytes, presumably
stimulated by EBV infection. This is believed to be related to the
failure of the immune system, especially the T-cell population, which
is suppressed by drugs such as cyclosporine, to respond
normally to EBV-infected B lymphocytes.16 17 The fact
that
the risk of LPD and the mortality from it increases with the duration
of immunosuppression adds validity to this theory. In approximately
89% of patients in whom BCL developed within 1 year of
transplantation, there was complete regression of the lesions after
reduction of immunosuppressive therapy alone.18 19
Thus,
the decrease in number or function of EBV-CTL may allow for unchecked
proliferation of EBV-driven LPD.
One report on EBV-associated LPD after allogeneic bone marrow
transplantation documented successful eradication of disease after
infusions of donor-derived pooled leukocytes. Because of the known
high-frequency of EBV-specific CTL precursors in the blood of
seropositive normal donors, it is reasonable to suggest that
donor-derived EBV-reactive T cells had a critical role in the
response noted. More specific therapy with just EBV-CTL may provide a
tailored approach with less systemic side effects. Continued study of
the mechanisms underlying the cause of EBV-driven LPD and the cellular
immune response, including the EBV-specific CTL response to it, may
provide novel treatment strategies against BCLs in the
organ-transplant recipient.
 |
Selected Abbreviations and Acronyms
|
|---|
| BCL |
= |
B-cell lymphoma |
| CTL |
= |
cytotoxic T lymphocytes |
| EBV |
= |
Epstein-Barr virus |
| EBV-CTL |
= |
CTLs specific against EBV |
| FACS |
= |
flow cytometric analysis |
| Ig |
= |
immunoglobulin |
| LPD |
= |
lymphoproliferative disorders |
| SCID |
= |
severe combined immunodeficient mice |
|
 |
Acknowledgments
|
|---|
The secretarial assistance of Maureen Coyle is gratefully
acknowledged.
 |
Footnotes
|
|---|
Reprint requests to J. Michael DiMaio, MD, Department of Surgery,
PO
Box 3050, Duke University Medical Center, Durham, NC 27710.
 |
References
|
|---|
-
Penn I. Principles of tumor immunity:
immunocompromised patients. In: DeVita VT Jr, Rosenberg SA,
eds. AIDS-Etiology, Diagnosis, Treatment and Prevention,
H.S. Philadelphia, Pa: WB Saunders; 1990:1-14.
-
Malatack JJ, Gartner JC Jr, Urbach AH, Zitelli BJ.
Orthotopic liver transplantation, Epstein Barr virus,
cyclosporine, and lymphoproliferative disease: a growing
concern. J Pediatr. 1991;118:667-675. [Medline]
[Order article via Infotrieve]
-
Moss DJ, Rickinson A, Pope JH, et al. Long term
T cell mediated immunity to Epstein Barr virus in man, III: activation
of cytotoxic T cells in virus infected leukocyte cultures.
Int J Cancer. 1979;23:618. [Medline]
[Order article via Infotrieve]
-
Mosier DE, Gulizia R, Baird SM, Wilson DB.
Transfer of a functional human immune system to mice with severe
combined immunodeficiency. Nature. 1988;335:256-259. [Medline]
[Order article via Infotrieve]
-
Cannon MJ, Pisa P, Fox RI, Cooper NR.
Epstein-Barr virus induces aggressive lymphoproliferative
disorders of human B cell origin in SCID/hu chimeric mice.
J Clin Invest. 1990;85:1333-1337.
-
Boyle T, Tamburinin M, Berend K, Kizilbash A, Borowitz
M, Lyerly H. Human B cell lymphoma in severe combined
immunodeficient mice after active infection with Epstein-Barr
virus. Surgery. 1992;112:378-386. [Medline]
[Order article via Infotrieve]
-
de Waele M, Thielmans C, Van Camp BKG.
Characterization of immunoregulatory T cell in EBV induced
infectious mononucleosis by monoclonal antibodies.
N Engl J Med. 1981;304:460. [Medline]
[Order article via Infotrieve]
-
Masucci MG, Bejarano MT, Masucci G, Klein E.
Large granular lymphocytes inhibit the in vitro growth of
autologous Epstein Barr virus infected B cells. Cell
Immunol. 1983;76:311. [Medline]
[Order article via Infotrieve]
-
Moss DJ, Wallace LE, Rickinson AB, Epstein MA.
Cytotoxic T cell recognition of Epstein Barr virus infected B
cells, I: specificity and HLA restriction of effector cells
reactivated in vitro. Eur J Immunol. 1981;11:686. [Medline]
[Order article via Infotrieve]
-
Lakhadar M, Senik A, Fridman WH. Human cytotoxic
T lymphocytes (CTL) against Epstein Barr virus (EBV) infected cells:
EBV specificity and involvement of major histocompatibility complex
determinants in the lysis exerted by anti-EBV CTL toward HLA-compatible
and allogeneic target cells. Cell Immunol. 1984;83:414. [Medline]
[Order article via Infotrieve]
-
Kieff E, Liebowitz D. In: Fields BN, ed.
Virology. New York, NY: Raven Press; 1990:1889-1920.
-
Klein G. Viral latency and transformation: the
strategy of Epstein Barr virus (EBV). Cell. 1989;58:5-8. [Medline]
[Order article via Infotrieve]
-
Murray RJ, Young LS, Calender A, et al.
Different patterns of Epstein-Barr virus gene expression and of
cytotoxic T-cell recognition in B-cell lines infected with transforming
(B95.8) or nontransforming (P3HR1) virus strains. J
Virol. 1988;62:894-901. [Abstract/Free Full Text]
-
Murray R, Kurilla M, Brooks J, et al.
Identification of target antigens for the human cytotoxic T cell
responses to Epstein Barr virus (EBV): implications for the immune
control of EBV-positive malignancies. J Exp
Med. 1992;176:157-168. [Abstract/Free Full Text]
-
Cohen JI. Epstein-Barr virus lymphoproliferative
disease associated with acquired immunodeficiency.
Medicine. 1991;70:137-160. [Medline]
[Order article via Infotrieve]
-
Cohen S, Ellwein L. Cell proliferation in
carcinogenesis. Science. 1990;249:1011-1016.
-
Adams J, Harris A, Pinkert C, et al. The
c-myc oncogene driven by immunoglobulin enhancers induce lymphoid
malignancy in transgenic mice. Nature. 1985;318:533.[Medline]
[Order article via Infotrieve]
-
Henderson S, Rowe M, Gregory C, et al. Induction
of bcl-2 expression by Epstein-Barr virus latent membrane protein 1
protects infected B cells from programmed cell death.
Cell. 1991;65:1107-1115. [Medline]
[Order article via Infotrieve]
-
McDonnell T, Korsmeyer S. Progression from
lymphoid hyperplasia to high grade malignant lymphoma in mice
transgenic for the t(14;18). Nature. 1990;349:254-256.