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Immunology |
Division of Clinical Pharmacology, Department of Medicine, Ludwig-Maximilians-University of Munich, 80336 Munich, Germany
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ABSTRACT |
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 Top ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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and prostaglandin E2. Autologous
mononuclear cells were cocultured with DCs in the presence of
low-dose interleukin (IL)-2 and IL-7 and were restimulated
weekly with new DCs. High levels of IL-12 and IFN-
could be detected
in the supernatants, indicating a T-helper type 1-type immune
response. This cytokine profile was associated with the expression of
the activation marker CD69 on both T helper and CTLs and with an
antigen-induced proliferative T-cell response. After 4 weeks,
CTL-mediated cytotoxicity was assessed. Tumor cell lysis was specific
for Panc-1 tumor cells and was MHC class I-restricted. Cytokine
secretion, CD69 expression of T cells, and antigen-induced T-cell
proliferation correlated with the cytotoxic activity and were more
pronounced when KLH was added to the lysate. This is the first study to
show that T cells specific for pancreatic carcinoma cells can be
generated in vitro by lysate-pulsed DCs and that the
T-cell response can be enhanced by KLH. This in vitro
model can be applied to compare different strategies in the development
of DC-based tumor vaccines. |
INTRODUCTION |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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Potential targets for the immunotherapy of pancreatic carcinoma are antigens such as carcinoembryonic antigen (10 , 11) , HER-2/neu (12 , 13) , MUC-1 (14, 15, 16, 17) , mutant ras (18 , 19) , p53 (20 , 21) , and gangliosides (22) . However, vaccinating against a single antigen has disadvantages, because it is unknown which of the identified antigens have the potential to induce an effective antitumor immune response. Furthermore, immunity against a single antigen may be ineffective in tumors with heterogeneous cell populations and carries the risk of inducing tumor antigen escape variants (7) . In addition, this strategy is restricted to those patients with a specific HLA type.
The use of unfractionated tumor-derived antigens in the form of tumor cell lysates or whole tumor cells circumvents these disadvantages. Tumor lysates contain multiple known as well as unknown antigens that can be presented to T cells by both MHC class I- and class II-pathways (4 , 23 , 24) . Therefore, lysate-loaded DCs are more likely to induce a polyclonal expansion of T cells, including MHC class II-restricted T-helper cells. These have been recognized to play an important role in the activation of CTLs, probably the most important cells in effecting an antitumor immune response (25) . The generation of CTL clones with multiple specificities may be an advantage in heterogeneous tumors and could also reduce the risk of tumor escape variants. Furthermore, lysate from the autologous tumor can be used independently of the HLA type of the patient. A major drawback of unfractionated tumor antigens is the possibility of inducing an autoimmune reactivity to epitopes that are shared by normal tissues (26) . However, in clinical trials using lysate or whole tumor cells as the source of antigen, no clinically relevant autoimmune responses were detected (6 , 8 , 27) .
For the development of an effective tumor vaccine based on DCs, the influence of experimental parameters on the immune response remain to be determined, such as the optimal source and subtype of DCs, the choice of the tumor antigen preparation, methods for effectively introducing antigens into MHC class I- and II-processing pathways, and the use of activators and adjuvants. Because not all of these parameters can be optimized in controlled clinical trials, there is a need for in vitro models to address these questions.
In this study, we present an in vitro model designed in our laboratory to test different strategies for the development of a therapeutic vaccine against pancreatic carcinoma based on tumor lysate-pulsed DCs. Several parameters such as the cytokine profile, tumor antigen-induced T-cell proliferation, expression of T-cell activation markers, and cytolytic T-cell activity were assessed to characterize the immune response.
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MATERIALS AND METHODS |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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from R&D Systems
(Wiesbaden, Germany). PGE2, KLH, and FITC-dextran
were obtained from Sigma Chemical Co. (Munich, Germany).
[3H]thymidine was purchased from Amersham
Buchler (Freiburg, Germany) and [51Cr]sodium
chromate from NEN Life Sciences (Zavantem, Belgium).
Cell Culture.
Cell cultures from human peripheral blood mononuclear cells were
maintained in RPMI 1640 culture medium (Biochrom, Berlin, Germany)
supplemented with 2% human AB serum (BioWhittaker,
Walkersville, MD), 2 mM L-glutamine (Life
Technologies, Inc.), 50 units/ml penicillin, and 50 µg/ml
streptomycin (Sigma Chemical Co., Munich, Germany). The human
pancreatic carcinoma cell lines AsPc-1
(HLA-A2-), Panc-1
(HLA-A2+), and Capan-1
(HLA-A2+) were purchased from the European
Collection of Animal Cell Cultures (Salisbury, United Kingdom).
The gastric carcinoma cell line KATO-III
(HLA-A2-) was obtained from the American Type
Culture Collection. Cells were maintained in RPMI 1640 supplemented
with 10% FCS (Biochrom), 2 mM
L-glutamine, 50 units/ml penicillin, and 50 µg/ml
streptomycin.
Flow Cytometry Analysis.
Antibodies used to phenotype the cells were anti-HLA-DR-PE,
anti-CD80-PE, anti-CD86-PE, anti-CD83-FITC, anti-CD54-PE,
anti-HLA-ABC-FITC, anti-CD14-FITC, anti-CD8-PE, anti-CD4-PE,
anti-CD69-FITC (PharMingen, San Diego, CA), and anti-CD3-PerCP
(Becton Dickinson, San Jose, CA). For staining,
105 cells were suspended in 100 µl of PBS and
were incubated with 10 µl of the antibodies for 20 min on ice. Flow
cytometric analysis was performed on a FACS-Calibur (Becton
Dickinson).
Preparation of Tumor Cell Lysate.
Confluent cultures of pancreatic carcinoma cell lines were incubated
with 0.01% EDTA-solution for 10 min, carefully detached with a cell
scraper, washed twice in PBS, and resuspended at a density of
5 x 106/ml in serum-free medium.
The cell suspensions were frozen at -80°C and disrupted by four
freeze-thaw cycles. For the removal of crude debris, the lysate was
centrifuged for 10 min at 300 x g. The
supernatant was collected and passed through a 0.2-µm filter. The
protein concentration of the lysate was determined by a commercial
assay (Bio-Rad, Munich, Germany). Lysates were tested for endotoxin
contamination with the Limulus amoebocyte lysate assay
(BioWhittaker) according to the manufacturer’s instructions and were
found to be negative (endotoxin content <1 pg/ml).
Generation of Tumor Lysate-pulsed Mature DCs.
Monocyte-derived DCs were generated as described elsewhere
(28)
. In brief, MNC from healthy
HLA-A2+ donors were isolated from peripheral
blood by Ficoll-Hypaque gradient centrifugation and were subsequently
allowed to adhere in culture flasks for 1 h. The initially
adherent cell fraction was harvested and cultured in the presence of
GM-CSF (1000 units/ml) and IL-4 (1000 units/ml). On day 6, the cells
were incubated with lysate of pancreatic carcinoma cell lines at a
final concentration of 120 µg of protein/ml for 3 h. In some of
the experiments, KLH was added at a concentration of 25 µg of
protein/ml. Subsequently, DCs were activated with TNF- (1000
units/ml) and PGE2 (1 µM) for
24 h.
Endocytic Activity.
Endocytic activity of DCs was assessed by adding FITC-dextran (0.5
mg/ml) to the culture medium for 30 min at 37°C (control on ice).
Thereafter, cells were extensively washed, and the uptake of
FITC-dextran was analyzed by flow cytometry.
Coculture of DCs and T cells.
Nonadherent MNC from HLA-A2+ donors were
cocultured with autologous DCs in three parallel groups consisting of
unpulsed, lysate-pulsed, or lysate- plus KLH-pulsed DCs at a ratio of
20:1. Every 7 days the cells were restimulated with DCs, and low doses
of IL-2 (10 units/ml) and IL-7 (5 ng/ml) were added to the culture
medium. Fifty percent of the medium was replaced on days 3 and 5 after
each stimulation by fresh medium containing 25 units/ml IL-2 and 10
ng/ml IL-7.
Cytokine Assays.
Forty-eight h after restimulation with DCs, the supernatants of the
cocultures were collected, and the concentrations of IL-12 (p40 and
p70), IFN-, and IL-4 were measured by ELISA (Endogen, Woburn, MA).
Proliferative T-Cell Response.
To test DCs for their capacity to induce a proliferation of allogeneic
T cells, DCs were harvested and cocultured with 2 x 105 allogeneic nonadherent MNC/well in 96-well
round-bottomed microtiter plates at ratios ranging from 1:20 to 1:320.
To assess antigen-induced autologous T-cell proliferation, nonadherent
MNC were removed from the cocultures after two stimulations with
lysate- or lysate- plus KLH-pulsed DCs and restimulated with autologous
unpulsed or lysate-pulsed DCs. On day 4,
[3H]thymidine (1 µCi/well) was added, and
cells were harvested after 18 h. The amount of incorporated
[3H]thymidine was analyzed in a liquid
scintillation counter (Wallac, Turku, Finland).
Cytotoxicity Assay.
After four stimulations with DCs, the lytic activity of MNC was
assessed in an 18-h 51Cr-release assay. A
suspension of single carcinoma cells was incubated with 100 µCi
[51Cr]sodium chromate/106
cells for 1 h and washed five times. Tumor cells (5 x 103)/well were incubated with nonadherent
MNC from the cocultures at E:T ratios ranging from 80:1 to 10:1 in
round-bottomed 96-well microtiter plates. After 18 h, 100 µl of
supernatant of each well was collected, and radioactivity was measured
with a gamma counter (Wallac Oy, Turku, Finland). Specific lysis was
calculated by the formula: specific
51Cr-release = [(experimental
counts - spontaneous counts)/(maximal counts - spontaneous counts) x 100%]. To determine MHC
class I-restriction of tumor cell lysis in some assays, the target
cells were preincubated with the MHC class I-blocking antibody W6/32
(Serotec, Oxford, United Kingdom).
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RESULTS |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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. Upon a 48-h activation period with TNF- and
PGE2, DCs were characterized by a low endocytotic
activity for dextran, high expression of costimulatory molecules, MHC
class II and CD83 (Fig. 1)
, secretion of IL-12 (Fig. 3)
, and an
enhanced T-cell stimulatory capacity (Fig. 2
; unpulsed).
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Next, we assessed the T-cell stimulatory capacity of lysate-pulsed DCs
in an allogeneic mixed lymphocyte reaction. Interestingly, the pulsing
of DCs with lysate of three pancreatic carcinoma cell lines had
different effects on DC function (Fig. 2)
. Lysate of AsPc-1 activated
DCs, which was reflected by an increased expression of
costimulatory molecules and MHC-II as well as an enhanced T-cell
proliferation rate. However, CD83 expression was not induced. In
contrast, lysate of Capan-1 completely inhibited the T-cell stimulatory
capacity of DCs, without altering the surface marker expression.
Subsequent activation of DCs with TNF- and
PGE2 induced maturation, but the DCs were still
dysfunctional. Pulsing DCs with lysate of Panc-1 did not significantly
influence surface marker expression or T-cell proliferation rates, and
an activation with TNF- and PGE2 markedly
improved their T-cell stimulatory capacity.
For the long-term cocultures of DCs with T cells, we used
lysate of the HLA-A2+ cell line Panc-1 to load
immature DCs of HLA-A2+ donors at a final
concentration of 120 µg of protein/ml. DCs were subsequently
activated with TNF- and PGE2 for 24 h.
Lysate-pulsed DCs Induce a Th1 Cytokine Profile in Cocultures with
Autologous MNC.
Nonadherent MNC cocultured with autologous DCs were weekly
restimulated with DCs. DCs were either unpulsed or pulsed with lysate
in the absence or presence of KLH. High levels of IL-12 were detected
in the supernatants of MNC cocultured with mature DCs (Fig. 3)
. IL-12 secretion was enhanced in cultures in that antigens from tumor
lysates were presented by DCs. A further increase was observed when KLH
was added to the lysate. IFN- secretion was strongly dependent on
the presentation of tumor antigens by DCs, again with higher
levels detectable if KLH was added. In all of the cultures, IL-4 was
near or below the detection limit.
T Cells Cultured with Lysate-pulsed DCs Up-Regulate CD69.
CD69 expression is induced early in T-cell activation after
stimulation of the T-cell receptor (29)
and is expressed
by antigen-specific T cells secreting IFN- and TNF- (30
, 31)
. From the same coculture as above, T cells were removed
48 h after the second stimulation with DCs, and the expression of
CD69 was analyzed by flow cytometry. Whereas T cells cultured in the
absence of DCs did not express this activation marker (data not shown),
2.9% of the CTLs (CD8+) and 3.9% of the
T-helper cells (CD4+) expressed CD69 when
cocultured with mature DCs (Fig. 4)
. Coculture with tumor lysate-pulsed DCs enhanced CD69 expression of
both CTLs and T-helper cells to 8.3% and 9.4%, respectively. If KLH
was added to the lysate, 17.1% of the CTLs and 17.8% of the T-helper
cells expressed CD69.
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Proliferation rates showed a good correlation with CD69 expression
of T cells in all donors.
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. Lytic activity was enhanced in the cocultures with lysate- plus
KLH-pulsed DCs. KATO-III was lysed to a minor extent only, and the
lysis was comparable with that of Panc-1 by MNC that had been
cocultured with unpulsed DCs. To test whether tumor cell lysis was MHC
class I-restricted, we preincubated the tumor cells with a MHC class
I-blocking antibody. This substantially reduced tumor cell lysis (Fig. 7)
. To exclude unspecific lysis mediated by NK cells, which
contributed approximately 2–3% of the MNC at the end of the
coculture, cytotoxicity directed against NK cell-sensitive K562 cells
was assessed, but no significant lysis could be observed (<5%; data
not shown).
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DISCUSSION |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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, PGE2, IL-1ß, IL-6,
monocyte-conditioned media, and extracellular ATP (34
, 35) , or T cell-derived signals, such as CD40 ligand
(36)
. Matured DCs up-regulate costimulatory molecules,
secrete the T-cell differentiation factor IL-12, and present antigens
more effectively because of increased phenotypic stability and extended
half-life of MHC class I- and II-molecules (37)
.
Furthermore, immature DCs bear the danger of inducing nonproliferating,
IL-10-producing T cells, whereas mature DCs propagate the development
of Th1 cells (38)
. In respect of clinical applicability,
we activated DCs with a combination of TNF- and
PGE2, which has been shown previously
(39)
to induce a mature phenotype with high expression of
MHC class II, adhesion and costimulatory molecules, the secretion of
IL-12, and enhanced T cell-stimulatory capacity.
Recently (40
, 41)
, it has been postulated that DCs exposed
to stressed or necrotic tumor cells mature spontaneously without the
need of other activators. However, it cannot be excluded that this
effect was caused by infection of the cell lines with
Mycoplasma (42)
. In our hands, pulsing DCs with
lysate from pancreatic carcinoma cell lines did not induce maturation
as assessed by the lack of CD83 expression, but affected phenotype and
T-cell-stimulatory capacity of DCs depending on the carcinoma cell line
that was used. Enhanced T-cell stimulation of AsPc-1-pulsed DCs
correlated with an increased surface expression of MHC class II and
costimulatory molecules. Pulsing DCs with lysate of Panc-1 had no
influence on surface marker expression or T-cell-stimulatory capacity,
whereas lysate of Capan-1 completely inhibited DC-mediated T-cell
proliferation. This inhibition did not correlate with the phenotype of
the DCs and could not be reversed by subsequent activation with TNF-
and PGE2. Because viability and
phenotype were not altered by Capan-1, soluble factors produced by the
tumor cell line could be responsible for this dysfunction. It has been
reported (43)
that tumor cells produce factors impairing
DC function, such as transforming growth factor ß, IL-10, and
vascular endothelial growth factor; transforming growth factor ß
reduces the allostimulatory capacity of DCs but does not influence the
expression of MHC class II, CD54, or costimulatory molecules. IL-10 not
only reduces the allostimulatory capacity of DCs, but also induces
antigen-specific anergy of CTLs (44)
, whereas vascular
endothelial growth factor inhibits maturation of DCs (45)
.
Because functionally impaired DCs are less likely to induce effective
CTL responses, we conclude that lysate-pulsed DCs should be monitored
for their T-cell-stimulatory capacity before their use in clinical
trials.
The cytokine profile in cocultures of MNC with lysate-pulsed
DCs indicated the induction of a Th1 immune response with high levels
of IL-12 and IFN- and low levels of IL-4. The increased levels of
IL-12 in cultures with antigen-pulsed DCs can be explained by a
positive feedback activation of DCs by antigen-specific T cells via
mechanisms such as IFN- secretion and CD40-CD40L interaction
(36)
. Only small amounts of IFN- were detected in the
cocultures of MNC with unpulsed DCs compared with high amounts in the
cocultures with lysate-pulsed DCs. Thus, IFN- secretion most likely
reflects reactivity of T cells toward tumor antigens presented by DCs.
IFN- secretion correlated with CD69 expression by both CD4 and CD8
lymphocytes in the cocultures. Activation of both CTLs and T-helper
cells suggests that tumor antigens from lysates were presented via both
MHC class I- and II-pathways.
To achieve clonal expansion of tumor antigen-specific T cells, the cultures were restimulated weekly with lysate-pulsed DCs. After the third stimulation, T-cell proliferation in response to tumor antigens was significantly enhanced, indicating an increased frequency of tumor-specific T cells in the cocultures. To determine whether T-cell activation and proliferation induced by DC coculture correlated with tumor cell lysis, we tested CTLs from the cocultures for their lytic activity against Panc-1 pancreatic tumor cells. After four stimulations, effective killing of Panc-1 was observed, whereas the HLA-A2- carcinoma cell line KATO-III was not lysed to a significant extent. The lytic activity appeared to be mediated by CTLs specific for Panc-1, because tumor cell lysis was MHC class I-restricted. However, this in vitro system does not allow defining the precise antigen specificity of the CTLs, and it cannot be excluded that other than tumor-specific antigens as well as additional MHC molecules could be involved in the recognition of the tumor cells. Unspecific lysis mediated by NK cells, contributing less than 3% to the MNC in the cocultures, is unlikely because no significant lysis of NK-sensitive K562 cells was observed. In conclusion, CTLs generated by repeated in vitro stimulations with lysate-pulsed DCs were able to specifically recognize and kill pancreatic carcinoma cells.
Adjuvants may play a major role in the induction of immune
responses mediated by DCs (46
, 47)
. The adjuvant
properties of the highly immunogenic protein KLH have been used in
vaccination trials either by coadministration of KLH with the DC
vaccine (6
, 9
, 27) or by linkage of KLH to the relevant
antigens (48, 49, 50)
. We observed that loading DCs
concomitantly with lysate and KLH enhanced the T-cell response against
tumor antigens. Higher levels of IL-12 and IFN- were detected in the
supernatants, and an increased fraction of both CD4 and CD8 lymphocytes
expressed the activation marker CD69. Furthermore, T cells from the
cocultures with lysate- plus KLH-pulsed DCs proliferated to a higher
extent when rechallenged with tumor antigens presented by DCs, and they
lysed tumor cells more efficiently. These observations favor the
concept that KLH can serve as a helper antigen augmenting
tumor-specific immune responses (51)
. The simultaneous
presentation of helper antigens and tumor antigens by DCs may lead to
side-by-side activation of T cells specific for the helper and the
tumor antigen, thereby providing a feedback signal for the
antigen-presenting cell via CD40 ligation (36)
. The
up-regulation of costimulatory molecules as well as secretion of IL-12
by the DCs could enhance the immunogenicity of tumor antigens that are
otherwise not recognized by the immune system. Another mechanism
involved could be a direct activation of CTLs by CD40-activated DCs
(52)
. From our data, we conclude that KLH cannot be used
only as a tracer molecule in vaccination trials, but also as an
adjuvant for vaccines based on tumor lysate-pulsed DCs.
In summary, we demonstrated that CTLs specific for pancreatic carcinoma cells can be generated in vitro with tumor lysate-pulsed DCs. Vaccination of pancreatic carcinoma patients with lysate-pulsed DCs might offer an additional therapeutic option for these patients. Using autologous tumor cells for the generation of lysates may enable the immune system to generate a multiclonal T-cell response against a broad spectrum of tumor antigens expressed by the individual tumor. Furthermore, assuming that pancreatic carcinoma cells share common rejection antigens allogeneous carcinoma cell lines could be used as a source of antigen for patients who are not eligible for surgery (53) . However, the feasibility of this approach still needs to be addressed in additional experiments.
We present an in vitro model applicable to improve and to monitor tumor vaccines based on DCs pulsed with unfractionated tumor antigens. We are currently investigating the influence of several parameters on the antitumor T-cell response such as maturational status of DCs, tumor antigen preparation (e.g., unfractionated cell lysate, apoptotic tumor cells, apoptotic bodies, or tumor RNA), and the use of adjuvants to develop a DC-based tumor vaccine against pancreatic carcinoma.
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ACKNOWLEDGMENTS |
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FOOTNOTES |
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1 Both authors contributed equally to this
manuscript. 
2 Supported in part by FöFoLe Grant
Reg.-Nr216.
3 To whom requests for reprints should be
addressed, at Medizinische Klinik Innenstadt, Ziemssenstrasse 1, 80336
Munich, Germany. Phone: 49-89-51602378; Fax: 49-89-51604406; E-mail: Andreas.Eigler{at}med.uni-muenchen.de
4 The abbreviations used are: DC, dendritic cell;
GM-CSF, granulocyte macrophage colony-stimulating factor; IL,
interleukin; TNF, tumor necrosis factor; PGE2,
prostaglandin E2; KLH, keyhole limpet hemocyanin; MNC,
mononuclear cells; NK, natural killer; Th-1, T-helper type 1.
Received 2/ 5/01. Accepted 6/21/01.
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REFERENCES |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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synergize in the activation and maturation of human dendritic cells.. J. Immunol., 165: 4704-4709, 2000. cooperate to activate human dendritic cells: synergistic activation of interleukin 12 production.. J. Exp. Med., 186: 1603-1608, 1997.This article has been cited by other articles:
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  B.-Y. Tsai, Y.-L. Lin, and B.-L. Chiang Application of Interleukin-12 Expressing Dendritic Cells for the Treatment of Animal Model of Leukemia Experimental Biology and Medicine, August 1, 2009; 234(8): 952 - 960. [Abstract] [Full Text] [PDF]
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 C Bauer, F Bauernfeind, A Sterzik, M Orban, M Schnurr, H A Lehr, S Endres, A Eigler, and M Dauer Dendritic cell-based vaccination combined with gemcitabine increases survival in a murine pancreatic carcinoma model Gut, September 1, 2007; 56(9): 1275 - 1282. [Abstract] [Full Text] [PDF]
|
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 |
|
 T. H. Kang, J. H. Lee, C. K. Song, H. D. Han, B. C. Shin, S. I. Pai, C.-F. Hung, C. Trimble, J.-S. Lim, T. W. Kim, et al. Epigallocatechin-3-Gallate Enhances CD8+ T Cell-Mediated Antitumor Immunity Induced by DNA Vaccination Cancer Res., January 15, 2007; 67(2): 802 - 811. [Abstract] [Full Text] [PDF]
|
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|
 |
|
 X. Zheng, J. Koropatnick, M. Li, X. Zhang, F. Ling, X. Ren, X. Hao, H. Sun, C. Vladau, J. A. Franek, et al. Reinstalling Antitumor Immunity by Inhibiting Tumor-Derived Immunosuppressive Molecule IDO through RNA Interference J. Immunol., October 15, 2006; 177(8): 5639 - 5646. [Abstract] [Full Text] [PDF]
|
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 |
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 N. Tokunaga, T. Murakami, Y. Endo, M. Nishizaki, S. Kagawa, N. Tanaka, and T. Fujiwara Human Monocyte-Derived Dendritic Cells Pulsed with Wild-Type p53 Protein Efficiently Induce CTLs against p53 Overexpressing Human Cancer Cells Clin. Cancer Res., February 1, 2005; 11(3): 1312 - 1318. [Abstract] [Full Text] [PDF]
|
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M. Dauer, B. Obermaier, J. Herten, C. Haerle, K. Pohl, S. Rothenfusser, M. Schnurr, S. Endres, and A. Eigler Mature Dendritic Cells Derived from Human Monocytes Within 48 Hours: A Novel Strategy for Dendritic Cell Differentiation from Blood Precursors J. Immunol., April 15, 2003; 170(8): 4069 - 4076. [Abstract] [Full Text] [PDF]
|
|
|
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|
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L. Holtl, C. Zelle-Rieser, H. Gander, C. Papesh, R. Ramoner, G. Bartsch, H. Rogatsch, A. L. Barsoum, J. H. Coggin Jr., and M. Thurnher Immunotherapy of Metastatic Renal Cell Carcinoma with Tumor Lysate-pulsed Autologous Dendritic Cells Clin. Cancer Res., November 1, 2002; 8(11): 3369 - 3376. [Abstract] [Full Text] [PDF]
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M. Schnurr, C. Scholz, S. Rothenfusser, P. Galambos, M. Dauer, J. Robe, S. Endres, and A. Eigler Apoptotic Pancreatic Tumor Cells Are Superior to Cell Lysates in Promoting Cross-Priming of Cytotoxic T Cells and Activate NK and {gamma}{delta} T Cells Cancer Res., April 1, 2002; 62(8): 2347 - 2352. [Abstract] [Full Text] [PDF]
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Y. Kotera, K. Shimizu, and J. J. Mule Comparative Analysis of Necrotic and Apoptotic Tumor Cells As a Source of Antigen(s) in Dendritic Cell-based Immunization Cancer Res., November 1, 2001; 61(22): 8105 - 8109. [Abstract] [Full Text] [PDF]
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) or lysate- plus KLH-pulsed DCs (
) were
removed 7 days after the third stimulation and were cocultured with
unpulsed or lysate-pulsed DCs. Proliferation was assessed by
incorporation of [3H]thymidine during the last 18 h
of a 4-day culture.
