WT1 and immunotherapy

Wilms' tumor 1 (WT1) expression has been investigated in various human cancers as a target molecule for cancer immunotherapy. However, few studies have focused on WT1 expression in dogs. Firstly, cDNA of canine WT1 (cWT1) was molecularly cloned from normal canine kidney. The cross-reactivity of the anti-human WT1 monoclonal antibody (6F-H2) with cWT1 was confirmed via Western blotting using cells overexpressing cWT1. Immunohistochemical staining revealed that cWT1 expression was detected in all canine lymphoma tissues and in some normal canine tissues, including the kidney and lymph node...

The advent of novel strategies to generate leukemia-associated-antigen (LAA)-specific T cells for adoptive immunotherapies creates a demand for standardized good laboratory practice (GLP)-compliant enumeration assays to provide a secure clinical environment-whether it is to identify potential donors, define therapeutic doses for transplantation, or monitor clinical success. Here, we introduce a no-wash assay based on single-platform cell enumeration and Streptamer staining to determine the Wilms' tumor antigen 1 (WT1)-specific T cell immunity in clinical samples...

The Wilms' tumor 1 (WT1) antigen is expressed in solid and hematological malignancies, but not healthy tissues, making it a promising target for cancer immunotherapies. Immunodominant WT1 epitopes, the native HLA-A2/WT1126-134 (RMFPNAPYL) (HLA-A2/RMFPNAPYL epitope (WT1A)) and its modified variant YMFPNAPYL (HLA-A2/YMFPNAPYL epitope (WT1B)), can induce WT1-specific CD8(+) T cells, although WT1B is more stably bound to HLA-A*02:01. Here, to further determine the benefits of those two targets, we assessed the naive precursor frequencies; immunogenicity and cross-reactivity of CD8(+) T cells directed toward these two WT1 epitopes...

The Wilms' tumor oncogene protein (WT1) is a highly validated tumor antigen for immunotherapy. WT1-targeted immunotherapy has been extensively explored in multiple human trials in various cancers. However, clinical investigations using WT1 epitopes have generally focused on two peptides, HLA-restricted to HLA-A*02:01 or HLA-A*24:02. The goal of this study was to identify new epitopes derived from WT1, to expand the potential use of WT1 as a target of immunotherapy. Using computer-based MHC-binding algorithms and in vitro validation of the T cell responses specific for the identified peptides, we found that a recently identified HLA-A*24:02-binding epitope (239-247), NQMNLGATL (NQM), was also a strong CD8(+) T cell epitope for HLA-A*02:01 molecule...

Wilms' tumor 1 (WT1) is a promising target of new immunotherapies for acute myeloid leukemia (AML) as well as for other cancers. OCV-501 is a helper peptide derived from the WT1 protein. OCV-501 induced OCV-501-specific Type 1 T-helper (Th1) responses dose-dependently and stimulated helper activity of the specific Th1 cells in peripheral blood mononuclear cells from healthy donors. OCV-501 also enhanced the increase in WT1-killer peptide-specific cytotoxic T lymphocytes. OCV-501 stimulated the OCV-501-specific Th1 clones in an HLA class-II restricted manner and formed a complex with HLA class-II protein...

Several types of vaccine-delivering tumor-associated antigens (TAAs) have been developed in basic and clinical research. Wilms' tumor 1 (WT1), identified as a gene responsible for pediatric renal neoplasm, is one of the most promising TAA for cancer immunotherapy. Peptide and dendritic cell-based WT1 cancer vaccines showed some therapeutic efficacy in clinical and pre-clinical studies but as yet no oral WT1 vaccine can be administrated in a simple and easy way. In the present study, we constructed a novel oral cancer vaccine using a recombinant Bifidobacterium longum displaying WT1 protein...

AIM: In cancer immunotherapy, biomarkers are important for identification of responsive patients. This study was aimed to find biomarkers that predict clinical outcome of WT1 peptide vaccination. MATERIALS & METHODS: Candidate genes that were expressed differentially between long- and short-term survivors were identified by cDNA microarray analysis of peripheral blood mononuclear cells that were extracted from 30 glioblastoma patients (discovery set) prior to vaccination and validated by quantitative RT-PCR using discovery set and different 23 patients (validation set)...

Synthetic immunology based on rapidly-advancing gene-engineering and immunobiology has made novel anticancer adoptive immunotherapies, using gene-modified T lymphocytes to express cancer antigen-specific receptors, a reality. Various technological innovations have overcome recent difficulties and achieved clear and long-lasting clinical efficacy against tumors, while seeking more powerful effector gene-modified T cells has yielded serious treatment-related adverse events. In this article, along with introducing our clinical trial for a novel anti-leukemia adoptive immunotherapy regimen using gene-modified autologous lymphocytes to express leukemia antigen Wilms Tumor 1(WT1)-specific T cell receptor (TCR) against refractory acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS), we provide an overview of the current status of this emerging treatment option and discuss its future form in the context of neoantigens encoded by mutated genes in cancer cells and immune checkpoint inhibitors...

CD19-directed chimeric antigen receptor (CAR) T cells are clinically effective in a limited set of leukemia patients. However, CAR T-cell therapy thus far has been largely restricted to targeting extracellular tumor-associated antigens (TAA). Herein, we report a T-cell receptor-mimic (TCRm) CAR, termed WT1-28z, that is reactive to a peptide portion of the intracellular onco-protein Wilms Tumor 1(WT1), as it is expressed on the surface of the tumor cell in the context of HLA-A*02:01. T cells modified to express WT1-28z specifically targeted and lysed HLA-A*02:01+ WT1+ tumors and enhanced survival of mice engrafted with HLA-A*02:01+, WT1+ leukemia or ovarian tumors...

Due to its immunogenicity and overexpression concomitant with leukemia progression, Wilms tumor protein 1 (WT1) is of particular interest for immunotherapy of AML relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT). So far, WT1-specific T-cell responses have mainly been induced by vaccination with peptides presented by certain HLA alleles. However, this approach is still not widely applicable in clinical practice due to common limitations of HLA restriction. Dendritic cell (DC) vaccines electroporated with mRNA encoding full-length protein have also been tested for generating WT1-derived peptides for presentation to T-cells...

We assessed the efficacy of WT1 class I peptide and WT1 class II peptide pulsed dendritic cell(DC)therapy for a wide range of advanced cancers. This retrospective study included 60 advanced cancer patients who were vaccinated 5times or more in this clinic between September 2013 and December 2015. The clinical response was examined. This treatment was approved by the ethics panel at this institution. Sixty patients were injected an average of 6.15times with dendritic cells(DCs) (2.6×10 / 7 cells/injection)...

Specific immunotherapy for acute leukemia remains a great unmet need. Native unmodified monoclonal antibody therapies, while promising, are inadequately effective for these malignancies, and multiple mechanisms for failure have been described. Antibody-dependent cellular cytotoxicity or phagocytosis is the primary modality of mAb-mediated cell killing in vivo, but ultimately leads to relapse of the leukemias, in model systems and in humans. By use of a T-cell receptor mimic mAb ESKM, derived against a WT1 peptide expressed in complex with HLA-A*02:01, whose only mechanism of therapeutic action is ADCC, we evaluated the mechanisms of leukemic relapse from its potent therapeutic action in mouse xenograft models of human leukemia...

We formerly demonstrated that vaccination with Wilms' tumor 1 (WT1)-loaded autologous monocyte-derived dendritic cells (mo-DCs) can be a well-tolerated effective treatment in acute myeloid leukemia (AML) patients. Here, we investigated whether we could introduce the receptor for hyaluronic acid-mediated motility (RHAMM/HMMR/CD168), another clinically relevant tumor-associated antigen, into these mo-DCs through mRNA electroporation and elicit RHAMM-specific immune responses. While RHAMM mRNA electroporation significantly increased RHAMM protein expression by mo-DCs, our data indicate that classical mo-DCs already express and present RHAMM at sufficient levels to activate RHAMM-specific T cells, regardless of electroporation...

Successful cancer immunotherapy necessitates T cell proliferation and infiltration into tumor without exhaustion, a process closely links optimal maturation of dendritic cells (DC), and adjuvant promotes this process as an essential prerequisite. Poly(I:C) has contributed to adjuvant immunotherapy that evokes an antitumor response through the Toll-loke receptor 3 (TLR3)/TICAM-1 pathway in DC. However, the mechanism whereby Poly(I:C) acts on DC for T cell proliferation and migration remains undetermined. Subcutaneous injection of Poly(I:C) regressed implant tumors (WT1-C1498 or OVA-EG7) in C57BL/6 mice, which coincided with tumor-infiltration of CD8(+) T cells...

The WT1 gene encodes a transcription factor involved in regulation of many cellular processes, including proliferation, differentiation, mRNA processing and apoptosis, besides acting as a transcription repressor of growth factors and their receptors' genes. This gene is expressed at high levels in several types of cancers, including acute leukemias. In this regard, many studies have identified WT1 protein as a tumor antigen, considered a target molecule for clinical application in human acute leukemias. Immunotherapy using WT1 antigen has been effective in stimulating immune responses against leukemic cells...

There is much current excitement about the potential of cancer immunotherapy. WT1 is high on the National Cancer Institute's list of priority antigens for immune therapy. In this chapter we describe a protocol for a clinical trial using a WT1 peptide-based cancer vaccine.

For a peptide-pulsed dendritic cell (DC) vaccine to work effectively in cancer treatment, it is significant that the target protein is expressed in cancer cells. Wilms' tumor 1 (WT1) has been identified as a molecular target for immune cell therapy of cancer. We evaluated the protein expression levels of WT1 in various solid tumors, as well as mucin 1 (MUC1) or major histocompatibility complex (MHC) class l molecules. Seven hundred and thirty-eight patients whose tissue samples were examined by immunohistochemical analysis agreed to undergo DC vaccine therapy...

In order to select a suitable combination of cancer cell lines as an appropriate source of antigens for dendritic cell-based immunotherapy of ovarian cancer, we analyzed the expression level of 21 tumor associated antigens (BIRC5, CA125, CEA, DDX43, EPCAM, FOLR1, Her-2/neu, MAGE-A1, MAGE-A2, MAGE-A3, MAGE-A4, MAGE-A6, MAGE-A10, MAGE-A12, MUC-1, NY-ESO-1, PRAME, p53, TPBG, TRT, WT1) in 4 established ovarian cancer cell lines and in primary tumor cells isolated from the high-grade serous epithelial ovarian cancer tissue...

This study investigated the efficacy of minimal residual disease (MRD) monitoring and MRD-directed preemptive immunotherapy in high-risk myelodysplastic syndrome (MDS) patients who received allogeneic hematopoietic stem cell transplantation (HSCT). MRD assessment consisted of Wilms' tumor gene 1 (WT1) detection with PCR and leukemia-associated immunophenotypic pattern examination with multiparameter flow cytometry (FCM). Post-HSCT, 31 patients were positive for WT1, and 8, for FCM; positivity for WT1 (18.6 vs...

The immune system is a crucial player in the development of cancer. Once it is in imbalance and immunosuppressive mechanisms supporting tumor growth take over control, dendritic cell immunotherapy might offer a solution to restore the balance. There are several methods to manufacture dendritic cells but none of them has yet proven to be superior to others. In this chapter, we discuss the methodology using electroporation of mRNA encoding Wilms' tumor gene 1, survivin, and TriMix (mixture of caTLR4, CD40L, and CD70) to simultaneously load and mature dendritic cells...