Stimulation of autologous proliferative and cytotoxic T-cell responses by “leukemic dendritic cells” derived from blast cells in acute myeloid leukemia

Abstract Effective presentation of tumor antigens is fundamental to strategies aimed at enrolling the immune system in eradication of residual disease after conventional treatments. Myeloid malignancies provide a unique opportunity to derive dendritic cells (DCs), functioning antigen-presenting cells, from the malignant cells themselves. These may then co-express leukemic antigens together with appropriate secondary signals and be used to generate a specific, antileukemic immune response. In this study, blasts from 40 patients with acute myeloid leukemia (AML) were cultured with combinations of granulocyte-macrophage colony-stimulating factor, interleukin 4, and tumor necrosis factor α, and development to DCs was assessed. After culture, cells from 24 samples exhibited morphological and immunophenotypic features of DCs, including expression of major histocompatibility complex class II, CD1a, CD83, and CD86, and were potent stimulators in an allogeneic mixed lymphocyte reaction (MLR). Stimulation of autologous T-cell responses was assessed by the proliferative response of autologous T cells to the leukemic DCs and by demonstration of the induction of specific, autologous, antileukemic cytotoxicity. Of 17 samples, 11 were effective stimulators in the autologous MLR, and low, but consistent, autologous, antileukemic cytotoxicity was induced in 8 of 11 cases (mean, 27%; range, 17%-37%). This study indicates that cells with enhanced antigen-presenting ability can be generated from AML blasts, that these cells can effectively prime autologous cytotoxic T cells in vitro, and that they may be used as potential vaccines in the immunotherapy of AML.

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321. Co-Delivery of CD80 and GM-CSF Genes into Acute Myeloid Leukemia Cells with Self-Inactivating Lentiviral Vectors Enhances their Proliferation, Differentiation, and Stimulation of Allogeneic and Autologous T Cell Responses

Molecular Therapy ◽

10.1016/s1525-0016(16)43151-5 ◽

2002 ◽

Vol 5 (5) ◽

pp. S107

Keyword(s):

Acute Myeloid Leukemia ◽

T Cell ◽

Myeloid Leukemia ◽

T Cell Responses ◽

Leukemia Cells ◽

Gm Csf ◽

Cell Responses ◽

Acute Myeloid Leukemia Cells ◽

Acute Myeloid ◽

Stimulation Of

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Expression of Tumor-Associated Antigens (TAAs) in Acute Myeloid Leukemia (AML) Correlated with Specific T Cell Responses and Survival.

Blood ◽

10.1182/blood.v108.11.414.414 ◽

2006 ◽

Vol 108 (11) ◽

pp. 414-414

Author(s):

Jochen Greiner ◽

Michael Schmitt ◽

Li Li ◽

Krzysztof Giannopoulos ◽

Katrin Bosch ◽

...

Keyword(s):

T Cells ◽

Acute Myeloid Leukemia ◽

T Cell ◽

Clinical Outcome ◽

Immune Responses ◽

Dna Microarray ◽

Myeloid Leukemia ◽

T Cell Responses ◽

Cell Responses ◽

Acute Myeloid

Abstract Several Tumor-associated antigens (TAAs) are expressed in acute myeloid leukemia (AML) and elicit specific immune responses of CD8 positive T cells. These specific T cell responses against leukemic blasts expressing TAAs might play a critical role in the control of minimal residual disease (MRD) in AML. Therefore, we investigated whether TAAs inducing specific immune responses in AML patients were associated with the clinical outcome. A DNA-microarray analysis of 116 AML samples was performed to correlate expression of TAAs to the clinical outcome. In these AML patients specific T cell responses to TAAs were assessed by ELISPOT analysis, tetramer staining and chromium release assays. Quantitative RT-PCR based validation of our results demonstrated the power of DNA microarray technology. We found a significant correlation of high mRNA expression of the TAA G250/CA9 with a longer overall survival (P=0.022), a trend for better outcome in patients with high expression levels of PRAME (P=0.103), and a hint for RHAMM/HMMR. In contrast, for other TAAs like WT1, TERT, PRTN3, BCL2, and LAMR1 we found no correlation with clinical outcome of AML patients. Moreover, co-expression of RHAMM/HMMR, PRAME and G250/CA9 provided a favorable prognostic effect (P=0.005). We found specific T cell responses at high frequency for these three antigens in AML patients. Positive immune reactions were detected in 8/17 (47%) AML patients for RHAMM/HMMR-R3-derived, in 7/10 (70%) for PRAME-P3-derived, and in 6/10 (60%) for newly characterized G250/CA9-G2-derived peptides. We detected a significant increased immune response of AML patients in complete remission compared to AML patients with refractory disease (P<0.001). Furthermore, we could demonstrate specific lysis of T2 cells and AML blasts presenting these epitope peptides RHAMM/HMMR-R3, PRAME-P3 and G250/CA9-G2. In conclusion, the expression of the TAAs RHAMM/HMMR, PRAME and G250/CA9 can induce strong anti-leukemic immune responses of CD8 positive T cells possibly enabling the control of MRD in AML patients. Thus, the antigens RHAMM/HMMR, PRAME and G250/CA9 represent interesting target structures for polyvalent immunotherapeutic approaches in AML.

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Mutated regions of nucleophosmin 1 elicit both CD4+ and CD8+ T-cell responses in patients with acute myeloid leukemia

Blood ◽

10.1182/blood-2011-11-394395 ◽

2012 ◽

Vol 120 (6) ◽

pp. 1282-1289 ◽

Cited By ~ 71

Author(s):

Jochen Greiner ◽

Yoko Ono ◽

Susanne Hofmann ◽

Anita Schmitt ◽

Elmar Mehring ◽

...

Keyword(s):

T Cells ◽

Acute Myeloid Leukemia ◽

T Cell ◽

Immune Responses ◽

Cd4 T Cells ◽

Myeloid Leukemia ◽

T Cell Responses ◽

Cd8 T Cell ◽

Cell Responses ◽

Acute Myeloid

Abstract Mutations in the nucleophosmin gene (NPM1mut) are one of the most frequent molecular alterations in acute myeloid leukemia (AML), and immune responses may contribute to the favorable prognosis of AML patients with NPM1mut. In the present study, we were able to demonstrate both CD4+ and CD8+ T-cell responses against NPM1mut. Ten peptides derived from wild-type NPM1 and NPM1mut were subjected to ELISPOT analysis in 33 healthy volunteers and 27 AML patients. Tetramer assays against the most interesting epitopes were performed and Cr51-release assays were used to show the cytotoxicity of peptide-specific T cells. Moreover, HLA-DR–binding epitopes were used to test the role of CD4+ T cells in NPM1 immunogenicity. Two epitopes (epitopes #1 and #3) derived from NPM1mut induced CD8+ T-cell responses. A total of 33% of the NPM1mut AML patients showed immune responses against epitope #1 and 44% against epitope #3. Specific lysis of leukemic blasts was detected. To obtain robust immune responses against tumor cells, the activation of CD4+ T cells is crucial. Therefore, overlapping (OL) peptides were analyzed in ELISPOT assays and OL8 was able to activate both CD8+ and CD4+ T cells. The results of the present study show that NPM1mut induces specific T-cell responses of CD4+ and CD8+ T cells and therefore is a promising target for specific immunotherapies in AML.

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Interleukin-12 Gene Expression into Acute Myeloid Leukemia-Derived Dendritic Cells Overcomes T-Cell Functional Impairment Induced by Leukemic Microenvironment.

Blood ◽

10.1182/blood.v104.11.1816.1816 ◽

2004 ◽

Vol 104 (11) ◽

pp. 1816-1816

Author(s):

Antonio Curti ◽

Simona Pandolfi ◽

Michela Aluigi ◽

Alessandro Isidori ◽

Isabella Alessandrini ◽

...

Keyword(s):

Gene Expression ◽

T Cells ◽

Acute Myeloid Leukemia ◽

Dendritic Cells ◽

T Cell ◽

Myeloid Leukemia ◽

Interleukin 12 ◽

Functional Features ◽

Ifn Γ ◽

Acute Myeloid

Abstract Acute myeloid leukemia (AML) cells are poorly immunogenic and release soluble factors inhibiting T-cell function. AML-derived dendritic cells (AML-DCs) have better antigen presentation capacity than leukemic blasts but share with AML cells some immunosuppressive features. In this study, we show that AML-DCs generated from CD14− AML samples (which represent 80% of total AML patients) are defective in IL-12 production. We, then, transfected CD14−-derived AML-DCs with IL-12 gene through the novel non-viral method nucleofection. IL-12 gene-nucleofected AML-DCs produce significant amount of IL-12 while maintain leukemia-specific karyotype, DC-like phenotype and function. In presence of the supernatant from the human leukemic cell line K562, allogeneic T-cell proliferation and interferon (IFN)-γ production induced by mock-transduced AML-DCs are significantly reduced. This effect is mainly directed on T cells, since AML-DC phenotype and cytokine production are not affected by leukemic supernatant. However, when stimulated by IL-12-producing AML-DCs, T cells produce higher concentrations of IFN-γ, thus maintaining a Th1 cytokine profile. In conclusion, IL-12 gene can be expressed into AML-DCs defective in endogenous IL-12 production by using a novel non-viral method which does not modify their phenotypical, cytogenetic and functional features. IL-12 gene expression into AML-DC counteracts the inhibitory effect of leukemic microenvironment on T lymphocytes

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Vaccination with synthetic analog peptides derived from WT1 oncoprotein induces T-cell responses in patients with complete remission from acute myeloid leukemia

Blood ◽

10.1182/blood-2009-10-250993 ◽

2010 ◽

Vol 116 (2) ◽

pp. 171-179 ◽

Cited By ~ 99

Author(s):

Peter G. Maslak ◽

Tao Dao ◽

Lee M. Krug ◽

Suzanne Chanel ◽

Tatyana Korontsvit ◽

...

Keyword(s):

Acute Myeloid Leukemia ◽

T Cell ◽

Complete Remission ◽

Myeloid Leukemia ◽

Peptide Vaccine ◽

T Cell Responses ◽

Interferon Γ ◽

Delayed Type Hypersensitivity ◽

Cell Responses ◽

Acute Myeloid

Abstract A pilot study was undertaken to assess the safety, activity, and immunogenicity of a polyvalent Wilms tumor gene 1 (WT1) peptide vaccine in patients with acute myeloid leukemia in complete remission but with molecular evidence of WT1 transcript. Patients received 6 vaccinations with 4 WT1 peptides (200 μg each) plus immune adjuvants over 12 weeks. Immune responses were evaluated by delayed-type hypersensitivity, CD4+ T-cell proliferation, CD3+ T-cell interferon-γ release, and WT1 peptide tetramer staining. Of the 9 evaluable patients, 7 completed 6 vaccinations and WT1-specific T-cell responses were noted in 7 of 8 patients. Three patients who were HLA-A0201-positive showed significant increase in interferon-γ–secreting cells and frequency of WT1 tetramer-positive CD8+ T cells. Three patients developed a delayed hypersensitivity reaction after vaccination. Definite related toxicities were minimal. With a mean follow-up of 30 plus or minus 8 months after diagnosis, median disease-free survival has not been reached. These preliminary data suggest that this polyvalent WT1 peptide vaccine can be administered safely to patients with a resulting immune response. Further studies are needed to establish the role of vaccination as viable postremission therapy for acute myeloid leukemia. This study was registered at www.clinicaltrials.gov as #NCT00398138.

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Interleukin-12p70 Expression by Dendritic Cells of HIV-1-Infected Patients Fails to Stimulategag-Specific Immune Responses

Clinical and Developmental Immunology ◽

10.1155/2012/184979 ◽

2012 ◽

Vol 2012 ◽

pp. 1-11 ◽

Cited By ~ 4

Author(s):

Ellen Van Gulck ◽

Nathalie Cools ◽

Derek Atkinson ◽

Lotte Bracke ◽

Katleen Vereecken ◽

...

Keyword(s):

T Cells ◽

Dendritic Cells ◽

T Cell ◽

Immune Responses ◽

T Cell Responses ◽

Hiv Replication ◽

Cell Responses ◽

Antigen Presenting ◽

Hiv 1 ◽

Unique Capability

A variety of immune-based therapies has been developed in order to boost or induce protective CD8+T cell responses in order to control HIV replication. Since dendritic cells (DCs) are professional antigen-presenting cells (APCs) with the unique capability to stimulate naïve T cells into effector T cells, their use for the induction of HIV-specific immune responses has been studied intensively. In the present study we investigated whether modulation of the activation state of DCs electroporated with consensus codon-optimized HxB2gagmRNA enhances their capacity to induce HIVgag-specific T cell responses. To this end, mature DCs were (i) co-electroporated with mRNA encoding interleukin (IL)-12p70 mRNA, or (ii) activated with a cytokine cocktail consisting of R848 and interferon (IFN)-γ. Our results confirm the ability of HxB2gag-expressing DCs to expand functional HIV-specific CD8+T cells. However, although most of the patients had detectablegag-specific CD8+T cell responses, no significant differences in the level of expansion of functional CD8+T cells could be demonstrated when comparing conventional or immune-modulated DCs expressing IL-12p70. This result which goes against expectation may lead to a re-evaluation of the need for IL-12 expression by DCs in order to improve T-cell responses in HIV-1-infected individuals.

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Immune Responses to RHAMM in Patients with Acute Myeloid Leukemia after Chemotherapy and Allogeneic Stem Cell Transplantation

Clinical and Developmental Immunology ◽

10.1155/2012/146463 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9 ◽

Cited By ~ 8

Author(s):

R. Casalegno-Garduño ◽

C. Meier ◽

A. Schmitt ◽

A. Spitschak ◽

I. Hilgendorf ◽

...

Keyword(s):

T Cells ◽

Acute Myeloid Leukemia ◽

Stem Cell ◽

T Cell ◽

Stem Cell Transplantation ◽

Cell Transplantation ◽

Allogeneic Stem Cell Transplantation ◽

Myeloid Leukemia ◽

Cell Responses ◽

Acute Myeloid

Leukemic blasts overexpress immunogenic antigens, so-called leukemia-associated antigens like the receptor for hyaluronan acid-mediated motility (RHAMM). Persistent RHAMM expression and decreasing CD8+T-cell responses to RHAMM in the framework of allogeneic stem cell transplantation or chemotherapy alone might indicate the immune escape of leukemia cells. In the present study, we analyzed the expression of RHAMM in 48 patients suffering from acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Furthermore, we correlated transcripts with the clinical course of the disease before and after treatment. Real-time quantitative reverse transcriptase polymerase chain reaction was performed from RNA of peripheral blood mononuclear cells. T cell responses against RHAMM were assessed by tetramer staining (flow cytometry) and enzyme-linked immunospot (ELISPOT) assays. Results were correlated with the clinical outcome of patients. The results of the present study showed that almost 60% of the patients were RHAMM positive; specific T-cells recognizing RHAMM could be detected, but they were nonfunctional in terms of interferon gamma or granzyme B release as demonstrated by ELISPOT assays. Immunotherapies like peptide vaccination or adoptive transfer of RHAMM-specific T cells might improve the immune response and the outcome of AML/MDS patients.

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Inhibition of invariant chain expression in dendritic cells presenting endogenous antigens stimulates CD4+ T-cell responses and tumor immunity

Blood ◽

10.1182/blood-2003-06-1867 ◽

2003 ◽

Vol 102 (12) ◽

pp. 4137-4142 ◽

Cited By ~ 23

Author(s):

Yangbing Zhao ◽

David Boczkowski ◽

Smita K. Nair ◽

Eli Gilboa

Keyword(s):

T Cells ◽

Dendritic Cells ◽

T Cell ◽

Cd4 T Cells ◽

T Cell Responses ◽

Cd4 T Cell ◽

Cytotoxic T Cell ◽

Invariant Chain ◽

Cell Responses ◽

Stimulation Of

Abstract Induction of potent and sustained antiviral or antitumor immunity is dependent on the efficient activation of CD8+ and CD4+ T cells. While dendritic cells constitute a powerful platform for stimulating cellular immunity, presentation of endogenous antigens by dendritic cells transfected with nucleic acid-encoded antigens favors the stimulation of CD8+ T cells over that of CD4+ T cells. A short incubation of mRNA-transfected dendritic cells with antisense oligonucleotides directed against the invariant chain enhances the presentation of mRNA-encoded class II epitopes and activation of CD4+ T-cell responses in vitro and in vivo. Immunization of mice with the antisense oligonucleotide-treated dendritic cells stimulates a more potent and longer lasting CD8+ cytotoxic T-cell (CTL) response and enhances the antitumor efficacy of dendritic cell-based tumor vaccination protocols. Transient inhibition of invariant chain expression represents a simple and general method to enhance the stimulation of CD4+ T-cell responses from endogenous antigens. (Blood. 2003;102:4137-4142)

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PD-1/PD-L1 interactions inhibit antitumor immune responses in a murine acute myeloid leukemia model

Blood ◽

10.1182/blood-2009-03-206672 ◽

2009 ◽

Vol 114 (8) ◽

pp. 1545-1552 ◽

Cited By ~ 244

Author(s):

Long Zhang ◽

Thomas F. Gajewski ◽

Justin Kline

Keyword(s):

Acute Myeloid Leukemia ◽

T Cell ◽

Myeloid Leukemia ◽

Cell Function ◽

Immune Escape ◽

Hematologic Malignancy ◽

T Cell Responses ◽

Cell Responses ◽

Programmed Death ◽

Acute Myeloid

Abstract Negative regulatory mechanisms within the solid tumor microenvironment inhibit antitumor T-cell function, leading to evasion from immune attack. One inhibitory mechanism is up-regulation of programmed death-ligand 1 (PD-L1) expressed on tumor or stromal cells which binds to programmed death-1 (PD-1) on activated T cells. PD-1/PD-L1 engagement results in diminished antitumor T-cell responses and correlates with poor outcome in murine and human solid cancers. In contrast to available data in solid tumors, little is known regarding involvement of the PD-1/PD-L1 pathway in immune escape by hematopoietic cancers, such as acute myeloid leukemia (AML). To investigate this hypothesis, we used the murine leukemia, C1498. When transferred intravenously, C1498 cells grew progressively and apparently evaded immune destruction. Low levels of PD-L1 expression were found on C1498 cells grown in vitro. However, PD-L1 expression was up-regulated on C1498 cells when grown in vivo. PD-1−/− mice challenged with C1498 cells generated augmented antitumor T-cell responses, showed decreased AML burden in the blood and other organs, and survived significantly longer than did wild-type mice. Similar results were obtained with a PD-L1 blocking antibody. These data suggest the importance of the PD-1/PD-L1 pathway in immune evasion by a hematologic malignancy, providing a rationale for clinical trials targeting this pathway in leukemia patients.

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