Loss of HLA Class-I Expression In Leukemic Cells That Relapsed After HLA-Matched and -Mismatched SCT

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2541-2541
Author(s):  
Yukio Kondo ◽  
Takamasa Katagiri ◽  
Kohei Hosokawa ◽  
Kinya Ohata ◽  
Hirohito Yamazaki ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Myeloid Leukemia ◽  
Hla Class I ◽  
Class I ◽  
Leukemic Cells ◽  
Leukemia Cells ◽  
Hla Class I Antigens ◽  
Ifn Γ

Abstract Abstract 2541 Background: The loss or down-regulation of HLA class-I antigens often occurs in solid tumors, but it is rarely demonstrated in leukemic cells. This phenomenon may explain why leukemic cells are immunogenic to some degree with allogeneic hematopoietic stem cell transplantation (allo-SCT) or donor leukocyte infusion, because HLA class-I antigens on leukemic cells are thought to present minor histocompatibility antigens (mHAs) and leukemia-associated antigens (LAAs) to donor T cells to elicit anti-leukemic cytotoxic T-cell (CTL) responses. Recent analyses of leukemic cells that relapsed after HLA-haploidentical SCT revealed that the leukemic cells lose their unshared HLA haplotype expression as a result of acquired uniparental disomy (UPD) on the short arm of chromosome 6 (6p). The loss of HLA from leukemic cells may occur after transplantation from HLA-identical donors if CTLs specific to mHAs or LAAs play a substantial role in the eradication of leukemic cells. This study evaluated this hypothesis by investigating HLA class-I expression on leukemic cells from patients at both the time of diagnosis and relapse after allo-SCT from HLA matched and mismatched donors. Objectives/Methods: Leukemic cells were obtained from five patients with myeloid leukemia (1 CML, 4 AML) both at diagnosis and relapse after allo-SCT. HLA class-I expression on leukemic cells was determined by flow cytometry using monoclonal Abs specific for the HLA-A allele. SCT donors were an HLA-matched sibling, an HLA-A locus-mismatched mother, an HLA-B and C locus-mismatched father, and 2 HLA-matched unrelated donors. The copy number-neutral loss of heterozygosity on 6p in leukemic cells was analyzed by a single-nucleotide polymorphism (SNP) array in patients after haploidentical SCT. The origin of the patients' HLA alleles (paternal or maternal) was determined by family studies on HLA. The post-transplantation donor T-cell responses against the leukemic cells were analyzed with an IFN-γ secretion assay. Results: HLA-A expression of leukemic cells obtained at relapse after allo-SCT was down-regulated in all 5 patients compared to that of leukemic cell obtained at diagnosis. The patient possessing HLA-A2/A11 (Case 1) was the recipient of BM possessing HLA-A24/A11 showed that 66% of leukemic cells at relapse were deficient in HLA-A2 expression. Leukemic cells restored HLA-A2 expression when this patient relapsed after the 2nd SCT using HLA-A2-matched cord blood, but at lower level in comparison to the level at diagnosis (MFI at diagnosis 177 vs. MFI at relapse 101). In vitro, cell-surface HLA-A2 expression was completely restored when leukemic cells at the 2nd relapse were treated in culture with IFN-γ (200 U/mL) for 48 hr. HLA-A2 expression in the shared haplotype (A0206-B3902-Cw0702-DR0405) was unexpectedly missing in 12% of the relapsed leukemic cells in another patient (Case 2) with HLA-2 loci (HLA-B and -C)-mismatched BM (A3101-B5601-Cw0401-DR0901), and this proportion increased to 83% at relapse after 2nd allo-SCT from the same donor (Figure). IFN-γ failed to restore HLA-A2 expression (MFI without IFN-γ 32 vs. MFI with IFN-γ 10) in vitro, and the genomic DNA extracted from leukemic cells at relapse showed a UPD of 6p. Donor-derived T-cells stimulated with leukemia cells from case 2 at diagnosis in vitro secreted IFN-γ in response to leukemia cells at diagnosis better than leukemia cells at relapse (1.67% vs. 0.85%). Conclusion: Loss of HLA-class I antigen occurs frequently in myeloid leukemia cells at relapse after allo-SCT regardless of the HLA disparities. T-cell attacks specific to the major as well as the mHAs, and LAAs may favor proliferation of leukemic cells deficient in the expression of HLA class-I. Disclosures: No relevant conflicts of interest to declare.

Redirected CD4+ T Cells towards HLA Class I-Restricted WT1 Epitope Successfully Display Multifactorial Helper Function for the Enhancement of Antileukemia Efficacy Mediated by Redirected T-Cell Based Immunocelltherapy.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3153-3153
Author(s):  
Yukihiro Miyazaki ◽  
Hiroshi Fujiwara ◽  
Toshiki Ochi ◽  
Sachiko Okamoto ◽  
Hiroaki Asai ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Hla Class I ◽  
Class I ◽  
Leukemia Cells ◽  
Proliferation And Differentiation ◽  
Ifn Γ

Abstract Abstract 3153 Purpose: In antitumor adoptive immunotherapy, the utility of tumoricidal CD8+ T cells are mainly highlighted, while in tumor immunity, the importance of tumor-reactive CD4+ T cells is also well documented. However, because the number of well-characterized tumor-associated epitopes recognized by CD4+ T cells still remains small, application of tumor-reactive CD4+ T cells is limited. In order to circumvent this drawback, redirection of CD4+ T cells to well-characterized HLA class I-restricted CD8+ T-cell epitope seems promising. In this study, using an HLA class I-restricted and WT1-specific T-cell receptor (TCR) gene transfer, we, in detail, examined helper functions mediated by those gene-modified CD4+T cells in redirected T cell-based antileukemia adoptive immunotherapy. Methods: HLA-A*2402-restricted and WT1235–243-specific TCR α/β genes were inserted into our unique retroviral vector encoding shRNAs for endogenous TCRs (WT1-siTCR vector), and was employed for gene-modification both of CD4+ and CD8+ T cells to express WT1-specific TCR. (1) WT1 epitope-responsive cytokine production mediated by WT1-siTCR-transduced CD4+ T cells (WT1-siTCR/CD4) was measured using bead-based immunoassay and ELISA assay. (2) WT1 epitope-ligation induced co-stimulatory molecules by WT1-siTCR/CD4 was assessed using flow cytometry. (3) Impacts on WT1 epitope and leukemia-specific responses; cytocidal activity, proliferation and differentiation into memory T-cell phenotype, mediated by WT1-siTCR-transduced CD8+ T cells (WT1-siTCR/CD8) provided by concurrent WT1-siTCR/CD4 were assessed using 51Cr-release assay, CD107a/intracellular IFN-γ assay, CFSE dilution assay and flow cytometry. (4) WT1 epitope-ligation triggered chemokine production mediated by WT1-siTCR/CD4 was assessed using real-time PCR, then chemotaxis mediated by WT1-siTCR/CD8 in response to those chemokines was assessed using a transwell experiment. (5) In vivo tumor trafficking mediated by WT1-siTCR/CD4 was assessed using bioluminescence imaging assay. (6) Finally, WT1-siTCR/CD4-caused in vivo augmentation of antileukemia functionality mediated by WT1-siTCR/CD8 was assessed similarly using a xenografted mouse model. Results: WT1-siTCR/CD4 showed a terminal effector phenotype; positive for transcription factor T-bet, but negative for Bcl-6 or Foxp3. Upon recognition of WT1 epitope, WT1-siTCR/CD4 produced Th1, but not Th2 cytokines in the context of HLA-A*2402, which simultaneously required HLA class II molecules on target cells. WT1 epitope-ligation enhanced WT1-siTCR/CD4 to express cell-surface OX40. In the presence of WT1-siTCR/CD4, but not non-gene-modified CD4, effector functions mediated by WT1-siTCR/CD8 in response to WT1 epitope and leukemia cells, including cytocidal activity based on CD107a expression and IFN-γ production was enhanced. Such augmentation was mediated by humoral factors produced by WT1 epitope-ligated WT1-siTCR/CD4. Additionally, proliferation and differentiation into memory phenotype, notably CD45RA- CD62L+ central memory phenotype, mediated by WT1-siTCR/CD8 in response to both WT1 epitope and leukemia cells were also augmented, accompanied with increased expression of intracellular Bcl-2 and cell-surface IL-7R. Next, CCL3/4 produced by activated WT1-siTCR/CD4 triggered chemotaxis of WT1-siTCR/CD8 which express the corresponding receptor, CCR5. Using bioluminescence imaging, intravenously infused WT1-siTCR/CD4 successfully migrated towards leukemia cells inoculated in a NOG mouse. Finally, co-infused WT1-siTCR/CD4 successfully augmented immediate accumulation towards leukemia cells and antileukemia reactivity mediated by WT1-siTCR/CD8 in a xenografted mouse model. Conclusion: Using GMP grade WT1-siTCR vector, redirected CD4+ T cells to HLA class I-restricted WT1 epitope successfully recognized leukemia cells and augmented in vivo antileukemia functionality mediated by similarly redirected CD8+ T cells, encompassing tumor trafficking, cytocidal activity, proliferation and differentiation into memory cells. The latter seem to support the longevity of transferred antileukemia efficacy. Taking together, coinfusion of redirected CD4+ T cells to HLA class I-restricted WT1 epitope seems feasible and advantageous for the successful WT1-targeting redirected T cell-based immunotherapy against human leukemia. Disclosures: No relevant conflicts of interest to declare.

Analysis of Memory T Lymphocytes Activity Following Stimulation with HLA-A24, A1 and Cw4 Restricted 9- and 10-mer Cytomegalovirus pp65 Overlapping Peptides.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2876-2876
Author(s):  
Monica Ghei ◽  
David F. Stroncek ◽  
Maurizio Provenzano
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Immune Therapy ◽  
Hla Class I ◽  
Class I ◽  
Specific Ctls ◽  
Over Time

Abstract In healthy subjects, primary infection with Cytomegalovirus (CMV) is usually mild or asymptomatic and is effectively controlled by the cell-mediated immune response. However, in immune compromised individuals, such as those with AIDS or after bone marrow transplantation, CMV reactivation is associated with significant morbidity until the individual’s immune system is completely reconstituted. One means of preventing post-transplant CMV infection is adoptive immunotherapy using CMV-specific cytotoxic T cells (CTLs) from the transplant donor. Several 9- and 10-mer HLA class I restricted peptides derived from the immune dominant CMV 65 kd matrix phosphoprotein (pp65) have been shown to produce CMV-specific CTLs. Two overlapping HLA-A24 restricted peptides have been specifically described: pp65 341–349 and pp65 341–350. These are 9- and 10-mer peptides that overlap except for the last amino acid phenylalanine (F) at the C-terminus [QYDPVAALF(F)]. Despite their similarity, the ability of these peptides to induce a T cell response has been reported to differ. Although it has been generally accepted that a unique CMV peptide is bound and presented by each separate HLA class I molecule, recent studies suggest that certain peptides are more promiscuous and may be presented by more than one HLA Class I antigen. For example, the 9-mer pp65 341–349 has been shown to stimulate CTLs from both HLA-A24 and Cw4 donors, while the 10-mer pp65 341–350 has been shown to be reactive with both HLA-A24 and A1 donors. The current investigation sought to compare the potency of these two peptides and determine the optimum peptide size for effective CMV adoptive immune therapy. Both peptides were tested for their ability to stimulate CMV-specific CTLs in HLA-A24, HLA-A1, and HLA-Cw4 restriction. In addition, a pp65 16-mer that included the 9- and 10-mers was tested for its ability to reactivate either CD8+ or CD4+ memory T cells. IFN-γ mRNA transcript as well as protein production were measured by in vitro cell culture assays. Peptide stimulations were performed on isolated CD8 and CD4 T lymphocytes by inducing the cells for 3 hours after a 2-week in vitro sensitization. The goal of the investigation was to determine whether both the 9- and the 10-mer peptides maintained high levels of CTL stimulation over time for all HLA restrictions studied. Moreover, it was important to investigate whether stimulation with the 16-mer, followed by restimulation by the two smaller peptides embedded within the larger sequence, led to effective T cell memory immune response. The 9- and 10-mer peptides effectively stimulated CTLs from HLA-A24, HLA-A1, and HLA-Cw4 CMV seropositive donors. Although both 9- and 10-mer were able to maintain high levels of stimulation over time for all restrictions, the 9-mer induced highest responses in cells expressing HLA-A24 (S.I. 4.07–528) or HLA-Cw4 (S.I. 4.15–483) while the 10-mer induced highest responses in cells expressing HLA-A24 (S.I. 3.5–528) or HLA-A1 (S.I. 8.25–615). The 16-mer peptide was also able to stimulate T cells from all HLA-A24, A1 and Cw4 donors (S.I. 6.95, 4.96, 5.02) at levels that are well maintained over time. This data confirmed that both the 9- and the 10-mer peptides are promiscuous and not restricted to a single HLA antigen. These peptides that have the ability to produce CMV-specific CTLs in patients with several different HLA types present a practical advantage over peptides that are restricted only to a single HLA type, and thus are optimal for CMV adoptive immune therapy.

Double Loading of Dendritic Cell MHC Class I and MHC Class II with an AML Antigen Repertoire Enhances Primary and Secondary T-Cell Responses In Vitro.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2529-2529
Author(s):  
William K. Decker ◽  
Dongxia Xing ◽  
Sufang Li ◽  
Simon N. Robinson ◽  
Hong Yang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mhc Class Ii ◽  
Cd8 T Cells ◽  
Class Ii ◽  
T Cell Response ◽  
Class I ◽  
Cross Presentation ◽  
Ifn Γ

Abstract Despite improvements in therapy for acute myelogenous leukemia (AML), a significant percentage of patients still relapse and succumb to their disease. Dendritic cell immunotherapy offers the promise of potentially effective supportive therapy for a variety of neoplastic conditions; and the use of DCs loaded with tumor antigens is now recognized as an important investigational therapy. Though a variety of methods have been used to load DC vaccines, the loading of the MHC class II compartment with tumor lysate has predominated. The priming of a class II-mediated (CD4) T-cell response may be crucial to the success of DC immunotherapy as such a response is likely required for the development of memory CD8+ T-cells. DC cross-presentation is credited with the ability of lysate-loaded DCs to prime both CD4 and CD8 T-cell responses, enabling the generation of CD8+ CTLs without the loading of the MHC class I compartment (i.e. the cytoplasm). Recently, however, several reports have raised doubts as to the efficiency of cross-presentation as a mechanism for CTL priming in vivo. To examine this issue, we have loaded human DCs with both AML tumor lysate and mRNA. This technique allows the full repertoire of class I antigens to be presented without dependence upon cross-presentation; and, moreover, provides a full complement of class II antigens necessary for CD4 T-cell priming and the generation of memory responses. Methods: CD14+ precursors were isolated from normal donor PBPCs by magnetic separation. Immature DCs were then generated by culturing precursors for six days in GM-CSF and IL-4. Lysate was produced by three successive freeze/thaw cycles of blasts. mRNA was extracted from blasts using Trizol and oligo-dT separation. Immature DCs were pulsed for three hours with AML lysate and subsequently electroporated with AML mRNA. Loaded DCs were matured for 48 hours with IL-1β, TNF-α, IL-6, and PGE2 and then used to prime autologous T-cells. Short-term responses were assayed on day 5 of the 1st stimulation. Memory responses were assayed on day 10 of a tertiary stimulation. Results: Doubly-loaded DCs can prime a superior T-cell response in vitro in comparison to that of singly-loaded DCs, demonstrating a 30–70% increase in IFN-γ ELISpots over lysate-loaded DCs (p<0.001) and a 3–4 fold increase in ELISpots in comparison to mRNA loaded DCs (p<0.001). These results were verified by flow cytometry which showed 35% of CD8+ T-cells primed by doubly-loaded DCs were CD69+/IFN-γ+ vs. 14% of CD8+ T-cells primed by lysate-loaded DCs (p<0.001). This enhancement may be based upon both an upregulation of CD83 surface expression (p<0.0019) of doubly-loaded DCs and/or the upregulation of B7.1/B7.2 that accompanies elevated CD40L signaling. Memory responses were also greatly improved, with a 126% increase in total ELISpots (double loaded DCs versus lysate loaded DCs; p<0.03) and a 187% increase in total IFN-γ secretion (p<0.03). Unloaded (p<0.01) and mRNA (p<0.007) loaded DCs exhibited a virtual inability to generate memory T-cells in vitro, suggesting that the perpetuation of the memory response is reliant upon T-cell help. Conclusion: DCs doubly-loaded with lysate and mRNA are more efficient in the generation of primary and secondary immune responses than are singly-loaded DCs. The clinical administration of such doubly-loaded DCs may offer an important therapeutic option to patients with AML.

Upregulated TCR Zeta and Improved the IFN-γ Secretion and Cytotoxicity in T Cell from Patients with AML after IL-2, IL-7 and IL-12 Stimulation

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5310-5310
Author(s):  
Shaohua Chen ◽  
Li Shi ◽  
Lijian Yang ◽  
Yuhong Lu ◽  
Gengxin Luo ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Myeloid Leukemia ◽  
Medical Science ◽  
Cell Receptor ◽  
Zeta Chain ◽  
Ifn Γ ◽  
Signaling Activation

Abstract T cells from patients with acute myeloid leukemia (AML) display antigen receptor–mediated signaling aberrations associated with defective T cell receptor (TCR) zeta chain, a subunit of the TCR/CD3 complex. Up-regulate TCR signaling activation by TCR zeta recombinant vector transfection was showed to reverse IL-2 production and increased the activation in T cells from patients with chronic myeloid leukemia. This study was undertaken to explore the possibility that increased TCR zeta gene expression stimulated with immune cytokines may upregulate T cell receptor signaling activation in T cells from patients with AML. CD3+ T cells sorted from peripheral blood of 8 cases with AML were induced with different immune cytokines, including IL-2, IL-7, IL-12, anti-CD3 and anti-CD28 antibodies in vitro. The result showed that TCR zeta chain protein was significantly upregulated after stimulation with IL-2 + IL-7 at 72 hours (p<0.05) by western-blot analysis, the expression of Zap-70 which is TCR zeta-associated protein was increased apparently after stimulation by combined IL-7 and IL-12 at 72 hours (p<0.05). A higher level of interferon (IFN)-γ secretion was showed obviously with single stimulating factor or combination with different cytokines (p<0.05), especially in IL-12 + IL-7, CD3 + CD28 + IL-2 or CD3 + CD28 + IL-7 combination. In addition, the cytotoxicity of T cell from patients with AML was achieved after stimulation with different cytokines combinations at 7 days, especially in CD3 + CD28 + IL-2 group and CD3 + CD28 + IL-2 + IL-12 group. These result showed that downregulation of the TCR zeta chain in T cell from patients with AML is a reversible event. Combined different cytokines could restore TCR zeta chain deficiency and enhance IFN-γ production and cytotoxicity in T cells from AML patients. It is possible that upregulated TCR zeta chain expression in T cell from AML patients will effectively increase or recover their activation of antileukemia cytotoxicity. Disclosures Chen: National Natural Science Foundation of China (no. 81100353, 81270604), the Fundamental Research Funds for the Central Universities (No. 21611447, 21612116), And Medical Science Foundation of Guangdong Province(A2011325): Research Funding.

scholarly journals Identification of T-Cell Receptors Specific to Antigens Presented By HLA-B4002 and B5401 in Acquired Aplastic Anemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3751-3751
Author(s):  
Kohei Hosokawa ◽  
Eiji Kobayashi ◽  
Yoshiki Akatsuka ◽  
Luis Espinoza ◽  
Noriharu Nakagawa ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Hla Class I ◽  
K562 Cells ◽  
Cell Receptor ◽  
Class I ◽  
Company Limited ◽  
Cd34 Cells ◽  
Ifn Γ ◽  
A Current

[Background] Leukocytes that lack HLA class I alleles derived from hematopoietic stem progenitor cells (HSPCs) that undergo copy number neutral loss of heterozygosity of the short arm of chromosome 6 (6pLOH) or HLA allelic mutations are often detected in acquired aplastic anemia (AA) patients. The presence of HLA class I allele-lacking leukocytes provides compelling evidence that cytotoxic T lymphocytes (CTLs) are involved in the development of AA. Our recent study showed that, among several HLA-class I alleles that are likely to be lost as a result of 6pLOH, HLA-B*40:02 is the most frequently lost allele in AA. Therefore, HLA-B*4002 is thought to play a critical role in the autoantigen presentation by HSPCs to CTLs. We previously identified the T-cell receptor (TCR) sequences from bone marrow (BM) CD8+ T cells in two CsA-dependent AA patients possessing B4002-lacking leukocytes (Case 1, Espinoza et al, Blood Adv, 2018) and B5401-lacking leukocytes (Case 2, Elbadry et al, Haematologica, 2019) by single-cell T-cell receptor (TCR) sequencing. Identifying the TCRs specific to antigens presented by these HLA class I alleles should allow us to screen autoantigens in AA. [Method] We established B4002+ or B5401+ K562 cell lines expressing CD80 and CD137L for the screening of antigen-specific T cell responses. To identify ligands of the TCR, we transfected peripheral blood (PB) T cells with a retrovirus vector containing different TCR cDNA derived from BM T cells and examined their responses to B4002+CD80+CD137L+ or B5401+CD80+CD137L+ K562 cells. Specific responses of each TCR transfectant to K562 cells or iPSC-derived CD34+ cells were determined using an enzyme-linked immunosorbent assay for detecting IFN-γ. Deep TCR sequencing of a current PB sample taken from the same patients was performed to determine whether or not T cells with specific TCRs persisted after successful immunosuppressive therapy (IST). [Results] In Case 1, two TCR transfectants (TCR-K1 and TCR-K2 which were the third- and second-most frequent TCRs in the BM T cells, respectively) secreted greater IFN-γ levels (1730 pg/mL and 2157 pg/mL, respectively) in response to B4002+CD80+CD137L+ K562 cells than those secreted by the other six transfectants (710 to 1184 pg/mL, respectively). TCR-K1 and TCR-K2 did not respond to an A2402+ counterpart (Figure). Notably, deep TCR sequencing of a current PB sample taken from Case 1 nine years after BM sampling revealed the persistence of the TCR-K1 sequence, suggesting that TCR-K1 may be responsible for CsA dependency of this patient. Deep TCR sequencing of other three AA patients with B4002-lacking leukocytes revealed decreased diversity of the T cell repertoire in CD8+ T cells but failed to reveal the same TCR motifs as Case 1. In Case 2, two TCR transfectants (TCR-K3 and TCR-K4) showed a specific response to B5401+CD80+CD137L+ K562 cells. Furthermore, these 2 TCR transfectants secreted higher amounts of IFN-γ (1.7 and 2.0 folds for TCR-K3 and TCR-K4, respectively) in response to wild-type iPSC-derived CD34+ cells than to B5401(-) CD34+ cells. [Conclusions] Our results suggest that these TCR transfectants recognized some intrinsic antigens derived from K562 cells in a B4002 or B5401-restricted manner. These TCR transfectants are the ideal tools for screening libraries of cDNA expressed by B4002+ COS/293T cells to identify autoantigens in AA. Figure Disclosures Yoroidaka: Ono Pharmaceutical: Honoraria. Nakao:Takeda Pharmaceutical Company Limited: Honoraria; Bristol-Myers Squibb: Honoraria; Alaxion Pharmaceuticals: Honoraria; Ohtsuka Pharmaceutical: Honoraria; Daiichi-Sankyo Company, Limited: Honoraria; Janssen Pharmaceutical K.K.: Honoraria; SynBio Pharmaceuticals: Consultancy; Chugai Pharmaceutical Co.,Ltd: Honoraria; Ono Pharmaceutical: Honoraria; Celgene: Honoraria; Kyowa Kirin: Honoraria; Novartis Pharma K.K: Honoraria.

scholarly journals Multi-Antigen Primed T Cells Promote Apoptosis of Acute Myeloid Leukemia (AML)

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4794-4794
Author(s):  
Ebtesam Nafie ◽  
Mathias Oelke ◽  
Melissa Valerio ◽  
Sojung Kim ◽  
Ivan Rodriguez ◽  
...  
Keyword(s):  
T Cells ◽  
Acute Myeloid Leukemia ◽  
T Cell ◽  
Myeloid Leukemia ◽  
Ex Vivo ◽  
Time Dependent ◽  
Target Cells ◽  
Ifn Γ ◽  
Acute Myeloid

Abstract Introduction Acute myeloid leukemia (AML), the most common acute leukemia in adults, is characterized by uncontrolled proliferation of immuature myeloid cells. Despite newly approved drugs, AML remains largely incurable due to the persistence of the leukemia stem cell (LSC) population which lie quiescent in the bone marrow niche. Immunotherapy has potential to eradicate LSCs, however, no unique LSC immunophenotype has been identified. Moreover, it is necessary to simultaneously target multiple antigens (Ags) to prevent immune escape and to overcome refractory disease. We present in vitro studies in support of a therapeutic platform capable of targeting multiple intracellular Ags which could meet this challenge. The adoptive transfer of activated T cells primed to engage diverse AML associated epitopes by ex vivo exposure to artificial Ag presenting cells (aAPC) has the potential to eliminate both primary leukemia blasts and LSCs. Hypothesis Ex vivo enrichment and expansion (E+E) of antigen-educated CD8+ T cells recognizing 5 peptides derived from 3 proteins, Cyclin A1, PRAME and WT1, can selectively identify, engage, and kill AML cell lines or patient-derived (PD) AML blasts in a HLA A*02:01 restricted manner in vitro. Materials and Methods T cells from the peripheral blood mononuclear cell fraction of a healthy HLA A*02:01 donor were enriched for antigen-educated CD8+/CD4 -T cells. These cells were cultured with nanoparticles decorated with the 5 peptides and a costimulatory protein, resulting in the activation and expansion of those T cells expressing the cognate T cell receptors. These cells are composed of ~97% abT cells, 3% gdT cells and ~13% T scm, 41.5% T cm, 39.5%T em, 6%T emra and 1% T n. Results Ex vivo expanded educated T cells exhibit target-specific anti-AML activity. T cell mediated cell apoptosis of HLA-matched THP1 cells is dose and time-dependent. At 10:1 effector to target (E:T) ratio, ~28% apoptosis occurred at 24 hrs, while apoptosis was at basal levels when antigen non-educated T cells were used (data not shown). Studies were extended to PD AML cells (Fig. 1A: 012; Fig. 1B: 415) where antigen educated T cells elicited rapid (&lt;16 hrs) and extensive (~90%) apoptosis of target PD AML cells at all E:T ratios examined. Time lapse photography of T cell/PD AML incubations revealed antigen-educated T cells clustered around AML cells (Fig. 2A), a fraction of the latter disappearing over the course of 12 hrs while PD AML cells incubated with non-educated T cells (Fig. 2B) remained viable over 12 hrs. Furthermore, there is little or no T cell movement or clustering in the wells with unprimed, non-active T cells. Release of IFN-γ by educated T cells. T cells (Fig.3A: antigen-educated through E+E) were incubated at E:T::5:1 for 24 to 48 hrs and IFN-γ in supernatants measured. The fold difference over non-educated T cells incubated with AML cells for the same time is shown and can reach over 5-fold. IFN-γ accumulation was time-dependent where antigen-educated T cells were combined with HLA-A2 matched THP1 or PD AML cells (012, 415, 470). Educated T cells were not active against target cells lacking HLA-A2 (K562) demonstrating HLA restricted killing (Fig. 3B). Additionally, antigen-educated T cells incubated without any target released slightly more IFN-γ than non-educated T cells under similar conditions but AML cells fail to stimulate IFN-γ release from non-educated T cells (data not shown). Conclusions We demonstrate HLA restricted cytotoxic activity of antigen-educated T cells against THP1 AML cells and PD AML blasts as shown by flow cytometry and microscopy. Consistent with target cell death, the supernatants from assays with antigen-educated T cells and HLA A*02:01 AML target cells exhibited over 5-fold more IFN-γ than media from assays of non-educated cells under identical conditions. Under these in vitro conditions, PD AML blasts were more readily killed than THP1 cells perhaps due to higher target antigen density (data not shown). These results support the use of multi-antigen-educated T cells for adoptive transfer to treat AML. To investigate the safety and establish the recommended phase II dose, a multi-center Phase I clinical study is underway in relapsed AML post-allo-HCT (NCT 04284228). Future studies will incorporate new antigens to enable broader targeting of a heterogeneous population of AML within and across patients Figure 1 Figure 1. Disclosures Oelke: Neximmune, Inc: Current Employment. Kim: Neximmune, Inc: Current Employment. Marcucci: Agios: Other: Speaker and advisory scientific board meetings; Novartis: Other: Speaker and advisory scientific board meetings; Abbvie: Other: Speaker and advisory scientific board meetings. Al Malki: Jazz Pharmaceuticals, Inc.: Consultancy; Hansa Biopharma: Consultancy; Neximmune: Consultancy; CareDx: Consultancy; Rigel Pharma: Consultancy.

Co-Administration Of Gene-Modified CD4+ T Cells Targeting HLA Class I-Restricted WT1 Epitope Diversely Enhances The Antitumor Effect Mediated By Redirected T-Cell Based Adoptive Immunotherapy Against Human Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 144-144
Author(s):  
Hiroshi Fujiwara ◽  
Fumihiro Ochi ◽  
Toshiki Ochi ◽  
Hiroaki Asai ◽  
Yukihiro Miyazaki ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mouse Model ◽  
Cd8 T Cells ◽  
Adoptive Immunotherapy ◽  
Cd4 T Cells ◽  
Hla Class I ◽  
Class I ◽  
Leukemia Cells

Abstract Purpose In the context of redirected T-cell based antitumor adoptive immunotherapy, the therapeutic roles played by co-infused CD4+ T cells genetically redirected to the predefined HLA class I-restricted epitope which had been originally recognized by effector CD8+ T cells has not yet been fully discussed. In this study, using an HLA class I-restricted WT1 -specific T-cell receptor (TCR) gene transfer, we in detail examined antileukemia functionality mediated by these gene-modified CD4+ T cells co-infused with similarly gene-modified effector CD8+ T cells as the redirected T cell-based adoptive immunotherapy. Methods Using our unique retroviral vector expressing HLA-A*2402-restricted and WT1235-243-specific TCR a/b genes and shRNAs for endogenous TCRs (WT1-siTCR vector), we genetically modified both CD4+ and CD8+ T cells from the same healthy donor or leukemia patients (termed WT1-siTCR/CD4 and WT1-siTCR/CD8, respectively). First, target-responsive cellular outputs mediated by WT1-siTCR/CD4 was thoroughly examined using flowcytometry, ELISA, 51Cr-release assay, CFSE dilution assay and bioluminescence assay. Next we similarly assessed impacts of WT1-siTCR/CD4 on the antileukemia functionality mediated by concurrentWT1-siTCR/CD8 both in vitro and in vivo. Eventually, we assessed the in vivo therapeutic efficacy of combined administration of WT1-siTCR/CD8 with WT1-siTCR/CD4 using a xenografted mouse model. Results The transcription factor profile demonstrated that WT1-siTCR/CD4 turned a terminal effector, but not regulatory phenotype. Activated WT1-siTCR/CD4 expressed cell-surface CD40L. Target-responsive cytokine production profile of WT1-siTCR/CD4 represented the Th1 helper function in the context of HLA-A*2402. HLA class II molecules expressed by leukemia cells facilitated the recognition of leukemia cells by WT1-siTCR/CD4 in the context of HLA-A*2402. WT1-siTCR/CD4 displayed the delayed cytocidal activity determined by 51Cr release assay. WT1-siTCR/CD4 could produce IFN-g in response to freshly isolated leukemia cells. WT1-siTCR/CD4 displayed the leukemia trafficking activity in vivo. WT1-siTCR/CD4 represented the potential to migrate into bone marrow via CXCR4/CXCL12 axis both in vitro and in vivo. Concurrent WT1-siTCR/CD4 augmented IFN-g production and cytotoxic degranulation mediated by WT1-siTCR/CD8 in response to the cognate epitope via humoral factors. Consequently, the cytocidal activity against autologous leukemia cells mediated by WT1-siTCR/CD8 was augmented in the presence of WT1-siTCR/CD4, both of them generated from normal lymphocytes of the same patient with leukemia in a complete remission. Upon the target recognition, activated WT1-siTCR/CD4 recruited WT1-siTCR/CD8 via CCL3/4-CCR5 axis. Proliferative response and differentiation into central memory T-cell subset mediated by WT1-siTCR/CD8 in response to the cognate epitope and leukemia cells were enhanced in the presence of autologousWT1-siTCR/CD4, but not gene-modified CD4+ T cells (NGM-CD4). CD127 expression on activated WT1-siTCR/CD8 also increased in parallel to this differentiation. Co-infused WT1-siTCR/CD4 augmented the tumor trafficking and persistence of WT1-siTCR/CD8 in vivo, resulting in the greater suppression of leukemia cells in a xenografted mouse model. Finally, in the therapeutic mouse model, co-infusion of WT1-siTCR/CD8 with of WT1-siTCR/CD4 significantly suppressed the growth of inoculated leukemia cells compared to that in mice received co-infusion of WT1-siTCR/CD8 with NGM-CD4 (Fig.1). Correlation between the therapeutic efficacy and survival of infused gene-modified T cells was also observed. Conclusion In results, the combined infusion of WT1-siTCR/CD8 with WT1-siTCR/CD4, but not NGM-CD4 obviously demonstrates the enhanced antileukemia efficacy via diverse mechanisms. Now we have just started a clinical trial using gene-modified T cells with WT1-siTCR vector for the treatment of patients with refractory acute myeloid leukemia and myeloid dysplastic syndrome. Because redirected T cells employed in this trial encompassed both WT1-siTCR/CD4 and WT1-siTCR/CD8, we are planning to clinically verify the significance of WT1-siTCR/CD4 in the redirected T cell-based antileukemia adoptive immunotherapy. (Fig.1) Disclosures: No relevant conflicts of interest to declare.

Characterization of T Cell Epitopes of the Receptor for Hyaluronic Acid Mediated Motility (RHAMM/CD168) in Acute Myeloid Leukemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2540-2540
Author(s):  
Michael Schmitt ◽  
Li Li ◽  
Mark Ringhoffer ◽  
Thomas Barth ◽  
Markus Wiesneth ◽  
...  
Keyword(s):  
T Cells ◽  
Acute Myeloid Leukemia ◽  
Hyaluronic Acid ◽  
T Cell ◽  
Cd8 T Cells ◽  
Myeloid Leukemia ◽  
Hla Class I ◽  
Class I ◽  
T Cell Epitopes ◽  
Acute Myeloid

Abstract To improve the clinical outcome of patients with acute myeloid leukemia (AML), immune therapies targeting leukemia associated antigens (LAAs) might be an approach complementary to chemotherapy and transplantation of hematopoetic stem cells. The receptor for hyaluronic acid mediated motility (RHAMM/CD168) has been defined as a LAA with specific expression. To define T cell epitopes of RHAMM/CD168 towards specific T cell immunotherapies, ten peptides were synthesized considering different computer algorithms and subjected to ELISPOT assays for interferon gamma and granzyme B, and to Cr-51 release assays. CD8+ T cells taken from the peripheral blood (PB) of 13 AML patients and presensitized with the RHAMM/CD168-derived peptides R3 (ILSLELMKL) or R5 (SLEENIVIL) did specifically recognize T2 cells pulsed with R3/R5. In contrast, CD8+ T cells isolated from the PB of 21 healthy volunteers were not able to lyse R3 or R5 pulsed T2 cells, even after presensitization. COS7 cells co-transfected with HLA-A*0201 and RHAMM/CD168 were lysed by R3 or R5 presensitized CD8+ T cells. Single HLA-A*0201 or RHAMM/CD168 transfected COS7 were not recognized. Cross-reactivity of the T cells was excluded by the use of unrelated peptides. K562 cells positive for RHAMM/CD168, but lacking HLA-class I molecules were not recognized indicating T cells and not NK cells as effector cells. The HLA class-I restricted lysis of COS-7 HLA-A*0201 and RHAMM/CD168 double- transfectants was confirmed by HLA class-I blocking antibody experiments. In an AML patient having received AML blast-derived dendritic cells, a higher frequency of RHAMM/CD168-peptide specific T cells was observed after four vaccinations when compared to his T cell status before vaccination. RHAMM/CD168 is also expressed in patients with other hematological malignancies which suggests a broad clinical applicability of its newly characterized T cell epitope peptides as a potential cancer vaccine.

Generation of Multi-Antigen Specific T Cells for Adoptive Immunotherapy of Myeloid Leukemia and Identification of MHC Class I and II-Restricted Peptides for WT1, Proteinase 3 and Human Neutrophil Elastase

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2985-2985
Author(s):  
Gerrit Weber ◽  
Ulrike Gerdemann ◽  
Nancy F. Hensel ◽  
Ann M. Leen ◽  
Catherine M. Bollard ◽  
...  
Keyword(s):  
T Cells ◽  
Myeloid Leukemia ◽  
Cytolytic Activity ◽  
Peptide Libraries ◽  
Class I ◽  
Human Neutrophil Elastase ◽  
Proteinase 3 ◽  
Healthy Donors ◽  
Ifn Γ

Abstract Abstract 2985 Generating cytotoxic T lymphocytes (CTL) against malignant cells using defined leukemia associated antigen (LAA) vaccines, or ex vivo adoptively transferred T cells, is a promising approach to prevent or treat leukemia. Vaccine or T cell therapies have largely focused on CD8 responses to defined HLA-A2 restricted LAA peptides. Strategies targeting single peptides are limited to the recipient's HLA type, lack of CD4 help, and risk of tumor immune escape. To overcome these constraints and develop T cell immunotherapy for patients with myeloid malignancies, we used entire peptide libraries of several LAA to generate multi-specific CD4+ and CD8+ leukemia–reactive CTL. We obtained 15mer peptide libraries overlapping by 11 aa for WT1, Proteinase 3 (Pr3), MAGE-A3, PRAME and human neutrophil elastase (HNE). PBMC of 10 healthy donors were stimulated with DC pulsed with peptide libraries of one antigen or the mix of 5 LAA (LAA mix). Cultures were re-stimulated weekly with peptide-pulsed DCs and peptide-recognition was tested by IFN γ-ELIspot. Positive cultures were further characterized by performing intracellular cytokine staining, measuring degranulation by CD107a release, and assessing in vitro cytolytic activity using peptide-pulsed autologous PHA blasts as targets in a flow cytometric killing assay. Nine out of 10 healthy donors responded to the LAA mix as assessed by IFN γ-ELIspot (mean: 471.2 SFU/2×105 cells, range: 296–968.5). The expanded CTL specifically recognized 3 antigens (mean, range 1–5), and PRAME was most frequently recognized (in 9 of 10 donors screened). Within donors we consistently saw recognition of the same profile of antigens irrespective of whether the CTL were induced with individual antigen or LAA mix, indicating that antigenic competition between LAA was not a limiting factor in our cultures. Correlating with ELIspot results, LAA CTL were cytotoxic to PHAB pulsed with the LAA mix (E:T=40:1; mean: 33.1%, range: 12.4–80.0%; negative control: PHAB: mean: 4.2%, range: 0–13.4%; n=7), as well as individual antigens (WT1: mean :12.2%, range: 0–26.1%; Pr3: mean: 9.7%, range: 5.6–13.7%; HNE: mean: 35.4%, range: 0–84.9%; MAGE-A3: mean: 19.9%, range: 15.2–28.2%; PRAME: mean: 16.7%, range: 3.8–37.5%). Cytotoxicity against the peptide library or the LAA mix was greater than against targets pulsed with the immunodominant peptide, demonstrating the benefit of a broad immune response. Cytolytic activity was also seen in donors with predominantly CD4+ response, suggesting a role for T helper cells in tumor lysis. The approach of stimulation with LAA mix was also feasible for epitope mapping. In addition to known peptides, we identified 16 new MHC class I and II-restricted peptides (WT1: 8, HNE: 6 and Pr3: 2). Thereby, up to 4 immunogenic peptides of two different antigens could be identified in one LAA mix culture. WT1 peptides showed class I and class II-restriction by blocking experiments with HLA antibodies. HNE peptides were mainly class I-restricted, with a dominant response against RRLACLFLACVLPAL in 5 of 7 donors. Thus, stimulation of healthy donor PBMC with LAA mix generates CTL without depending on known HLA-restrictions and may be a practical approach for adoptive immunotherapy of myeloid leukemia after stem cell transplantation. Moreover, the strategy enabled the identification of several new class I and II-restricted peptides. Importantly, in vitro cytolytic activity could also be shown for MHC class II-restricted peptides, indicating the importance of CD4+ T cells for anti-leukemia responses. Disclosures: No relevant conflicts of interest to declare.

Identification and Characterization of HLA Class I-Restricted MYD88 L265P-Derived Peptides As Tumor-Specific Targets for Immunotherapy

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2750-2750
Author(s):  
Annika Nelde ◽  
Juliane S Stickel ◽  
Daniel Johannes Kowalewski ◽  
Oliver Olaf Wolz ◽  
Lothar Kanz ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Hla Class I ◽  
Class I ◽  
Specific Cell ◽  
Specific Lysis ◽  
Effector Cells

Abstract Non-Hodgkin lymphomas (NHL) are frequent malignancies with considerable mortality. A recurrent somatic and oncogenic driver mutation in the Toll-like receptor adaptor gene MYD88, Leu265Pro (L265P) has been identified in up to 90% of certain NHL subtypes. Genetic alterations affecting a protein-coding region have the potential to generate mutation-derived peptides that are presented by HLA class I proteins and might be recognized by cytotoxic T cells. Because MYD88L265P is a widely occurring and tumor-specific mutation, we investigated the potential of MYD88L265P -containing peptides for CD8+ T cell mediated immunotherapy as a new therapeutic approach for MYD88L265P+ NHL. Based on in silico prediction we identified potential HLA ligands encompassing the MYD88L265P mutation for several HLA class I allotypes. Functional characterization of the candidate HLA class I MYD88L265P-derived HLA class I ligands with regard to induction of T cell responses identified a set of immunogenic peptides for HLA-B*07 and -B*15. In one MYD88L265P-mutated NHL patient, memory T cell responses targeting three different MYD88L265P-derived HLA class I ligands were detected by IFN-γ ELISPOT. Efficient T cell priming was demonstrated in vitro using naïve T cells of healthy volunteers (HVs). In detail, three HLA-B*07 peptides (P1-3B*07) and one HLA-B*15-restricted peptide (P4B*15) were analyzed using artificial antigen-presenting cell-based (aAPC) in vitro priming experiments in three to six HVs, respectively. For all tested peptides proliferation of peptide-specific CD8+ T cells could be detected after in vitro priming. For the HLA-B*07-restricted ligands, peptide-specific CD8+ T cells could be induced in 6/6 (P1B*15), 1/3 (P2B*07) and 3/4 (P3B*07) HVs, respectively, with a maximum frequency of 14.1% peptide-specific CD8+ T cells. For the HLA-B*15-restricted ligand (P4B*15), peptide-specific CD8+ T cells could be induced in 2/3 HVs with a maximum frequency of 9.5% tetramer-positive CD8+ T cells. The functionality and specificity of peptide-specific CD8+ T cells after aAPC-based in vitro priming was validated by intracellular cytokine staining for IFN-γ and TNF-α as well as for the expression of the degranulation marker CD107a. In 3/3 HVs primed with P1B*07 (RPIPIKYKAM) as well as in 1/2 HVs primed with P4B*15 (HQKRPIPIKY), we detected specific and functional CD8+ T cell populations after stimulation with the mutated peptides, but not after stimulation with the corresponding wild type peptides (P1WT: RLIPIKYKAM, P4WT: HQKRLIPIKY). Furthermore, the peptide-specific cytotoxic activity of specific CD8+ T cells was demonstrated in a VITAL assay. The polyclonal P1B*07- and P4B*15-specific CD8+ T cells (0.12% and 0.76% peptide-specific T cells, respectively) lysed autologous peripheral blood mononuclear cells loaded with the mutated peptides, but not cells presenting the wild type peptides. P4B*15-specific CD8+ T cells showed 17.9% (±1.2%) MYD88L265P-peptide-specific cell killing at an E/T ratio of 1:1 compared to 2.6% (±1.2%) of non-specific cell lysis of unspecific effector cells against the same targets in three independent replicates, respectively. The specific lysis showed an E/T ratio-dependent manner as the specific lysis decreases with reducing E/T ratios. P1B*07-specific CD8+ T cells specifically killed 11.4% (±1.7%) of MYD88L265P loaded targets at an E/T ratio of 0.7:1 in comparison to 2.1% unspecific lysis of unspecific effector cells. In this study, we identified and characterized MYD88L265P mutation-derived HLA class I ligands for T cell mediated immunotherapy. The strong immunogenicity of the HLA-B*07 and HLA-B*15-restricted mutation-derived peptides as well as the functionality and specificity of peptide-specific CD8+ T cells, demonstrated by cytotoxicity assays, underline the potential of the MYD88L265P mutation as tumor-specific target. These data highlight the potential of MYD88L265P mutation-specific immunotherapy as a novel broadly applicable and tumor-specific treatment approach for patients with MYD88L265P+ NHL. Disclosures Langerak: InVivoScribe: Patents & Royalties: Licensing of IP and Patent on BIOMED-2-based methods for PCR-based Clonality Diagnostics.; DAKO: Patents & Royalties: Licensing of IP and Patent on Split-Signal FISH. Royalties for Dept. of Immunology, Erasmus MC, Rotterdam, NL; Roche: Other: Lab services in the field of MRD diagnostics provided by Dept of Immunology, Erasmus MC (Rotterdam).

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