The Leucegene AML surfaceome atlas: immunotherapeutic target identification in AML
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ABSTRACT: We exploited the extensive genomic diversity of the Leucegene cohort of primary human AML specimens to provide an overview of the human AML surfaceome. Due to high cell number requirements, surface proteomics has been underexploited in AML so far, although surface proteome analysis of AML cell lines and small cohorts of primary human AML specimens paved the way for antigen identification23-25. Herein, we compared global and surface proteomic datasets generated from primary human AML specimens and show that surfaceome analysis uniquely identifies a larger subset of cell surface proteins compared to global proteomics. We therefore built a cohort of 100 primary human AML specimens that was subjected to surface proteome analysis and served as a primary dataset for antigen identification. A significant portion of the cohort also underwent single-cell RNA sequencing, which allowed the exploration of antigen expression at the population level and the selection of AML antigens expressed by primitive blasts. These analyses led to the identification of novel AML antigens expressed by the majority of AML specimens of the cohort, of antigens overexpressed by specific AML subgroups, as well as of previously uncovered potential leukemia stem cell (LSC) markers, and represents the first large-scale surface proteomic study in AML.
Project description:We exploited the extensive genomic diversity of the Leucegene cohort of primary human AML specimens to provide an overview of the human AML surfaceome. Due to high cell number requirements, surface proteomics has been underexploited in AML so far, although surface proteome analysis of AML cell lines and small cohorts of primary human AML specimens paved the way for antigen identification23-25. Herein, we compared global and surface proteomic datasets generated from primary human AML specimens and show that surfaceome analysis uniquely identifies a larger subset of cell surface proteins compared to global proteomics. We therefore built a cohort of 100 primary human AML specimens that was subjected to surface proteome analysis and served as a primary dataset for antigen identification. A significant portion of the cohort also underwent single-cell RNA sequencing, which allowed the exploration of antigen expression at the population level and the selection of AML antigens expressed by primitive blasts. These analyses led to the identification of novel AML antigens expressed by the majority of AML specimens of the cohort, of antigens overexpressed by specific AML subgroups, as well as of previously uncovered potential leukemia stem cell (LSC) markers, and represents the first large-scale surface proteomic study in AML.
Project description:The development of therapeutic anticancer vaccines calls for the identification of tumor-specific antigens (TSAs). Though a combination of four cutting-edge proteogenomic approaches, we performed a deep exploration of the MHC-I presented peptides (MAPs) of 19 acute myeloid leukemia (AML) patients and identified various TSAs that could serve for the design of an anti-AML vaccine.
Project description:Immunotherapy remains underexploited in AML compared to other hematological malignancies. Currently, gemtuzumab ozogamicin is the only therapeutic antibody approved for this disease. To identify potential targets for immunotherapeutic intervention, we analyzed the surface proteome of 100 genetically diverse primary human AML specimens for the identification of cell surface proteins and conducted single-cell transcriptome analysis on a subset of these specimens to assess antigen expression at the sub-population level. Through this comprehensive effort, we successfully identified numerous antigens and markers preferentially expressed by primitive AML cells. Many identified antigens are targeted by therapeutic antibodies currently under clinical evaluation for various cancer types, highlighting the potential therapeutic value of the approach. Importantly, this initiative led to the uncovering of AML heterogeneity at the surfaceome level, identifying several antigens and potential LSC markers characterising AML subgroups and positioning immunotherapy as a promising approach to target AML subgroup specificities.
Project description:The development of therapeutic anticancer vaccines calls for the identification of tumor-specific antigens (TSAs). Though a combination of four cutting-edge proteogenomic approaches, we performed a deep exploration of the MHC-I presented peptides (MAPs) of 19 acute myeloid leukemia (AML) patients and identified various TSAs that could serve for the design of an anti-AML vaccine.
Project description:The development of therapeutic anticancer vaccines calls for the identification of tumor-specific antigens (TSAs). Though a combination of four cutting-edge proteogenomic approaches, we performed a deep exploration of the MHC-I presented peptides (MAPs) of 19 acute myeloid leukemia (AML) patients and identified various TSAs that could serve for the design of an anti-AML vaccine.
Project description:The project aimed to profile the cell surface proteins of Nomo-1 (AML cell line) using structural surfaceomics for identification of protein conformation-based cancer antigens thereby expanding the toolkit for cancer target discovery for immunotherapeutic targeting. To achieve the goal, cell surface capture (CSC) was integrated with cross-linking mass spectrometry (XL-MS). PhoX was used as a cross-linker to freeze the structural conformations of protein in three-dimensional space, followed by biotinylation of cell surface proteins to enable enrichment of cell surface proteins to allow focused XL-MS analysis of those enriched proteins. PhoX having in-built phosphonate-based IMAC handle which allowed additional enrichment of cross-linked peptides.
Project description:Genome wide DNA methylation profiling of AML patient samples treated with PBS or DAC. The Illumina Infinium 450 Human DNA methylation was used to examine the methylation profile of 8 patient samples and 2 cell lines. Genome wide DNA methylation profiling of AML xenografts treated with either PBS control or with decitacine (DAC) alone, cytarabine (Ara-C) alone, DAC and Ara-C together (D+A), DAC followed by Ara-C (D/A) or with Ara-C followed by DAC (A/D). DNA was extracted from patient bone marrow samples and xenograft bone marrow samples using Qiagen Allprep kit. Bisulphite converted DNA from all samples were hybridised to the Illumina Infinium 450 Human Methylation arrays and for each analysis the drug treated sample was compared to the corresponding PBS control sample.
Project description:Therapy-related myelodysplasia or acute myeloid leukemia (t-MDS/AML) is a lethal complication of cancer treatment. Although t-MDS/AML development is associated with known genotoxic exposures, its pathogenesis is not well understood and methods to predict risk of development of t-MDS/AML in individual cancer survivors are not available. We performed microarray analysis of gene expression in samples from patients who developed t-MDS/AML after autologous hematopoietic cell transplantation (aHCT) for Hodgkin lymphoma (HL) or non-Hodgkin lymphoma (NHL) and controls that did not develop t-MDS/AML after aHCT. CD34+ progenitor cells from peripheral blood stem cell (PBSC) samples obtained pre-aHCT from t-MDS/AML cases and matched controls, and bone marrow (BM) samples obtained at time of development of t-MDS/AML, were studied. Significant differences in gene expression were seen in PBSC obtained pre-aHCT from patients who subsequently developed t-MDS/AML compared to controls. Genetic alterations in pre-aHCT samples were related to mitochondrial function, protein synthesis, metabolic regulation and hematopoietic regulation. Progression to overt t-MDS/AML was associated with additional alterations in DNA repair and DNA-damage checkpoint genes. Altered gene expression in PBSC samples were validated in an independent group of patients. An optimal 63-gene PBSC classifier derived from the training set accurately distinguished patients who did or did not develop t-MDS/AML in the independent test set. These results indicate that genetic programs associated with t-MDS/AML are perturbed long before disease onset, and can accurately identify those at risk of developing this complication. PBSC samples obtained pre-aHCT and BM samples at the time of development of t-MDS/AML post-HCT were studied. The training set consisted of 18 patients who developed t-MDS/AML (M-bM-^@M-^]casesM-bM-^@M-^]) after aHCT, matched with 37 controls who underwent aHCT, but did not develop t-MDS/AML. One to three controls were selected per case, matched for primary diagnosis (HL/NHL), age at aHCT (M-BM-110years), and ethnicity (Caucasians, African-Americans, Hispanics, other). The length of follow-up after aHCT for controls was longer than the time to t-MDS/AML in the corresponding case. The results of the training set were validated in an independent group of 36 patients (test set) consisting of 16 cases that developed t-MDS/AML post-aHCT and 20 matched controls. In the test set, 55 PBSC samples from 18 cases and 37 matched controls were studied. BM samples from time of development of t-MDS/AML were available for 12 cases, and from 21 matched controls obtained at a comparable time from aHCT. For validation, 36 PBSC samples from 16 cases and 20 matched controls were studied. All samples had been cryopreserved as mononuclear cells. After thawing, samples were labeled with anti-CD34-APC and anti-CD45-FITC and CD34+CD45dim cells were selected using flow cytometry. Total RNA was extracted using the RNeasy kit. RNA from 1000 cells was amplified and labeled using GeneChipM-BM-. Two-Cycle Target Labeling and Control Reagents from Affymetrix. 15 M-BM-5g of cRNA each was hybridized to Affymetrix HG U133 plus 2.0 Arrays. Microarray data were analyzed using R (version 2.9) with genomic analysis packages from Bioconductor (version 2.4). Data for PBSC and BM samples were normalized separately using robust multiarray averages with consideration of GC content (GCRMA). Probesets with low expression or variability were filtered. Expression of genes represented by multiple probesets was set as the median of the probesets. Using conditional logistic model (CLM) to retain matching between cases and controls, we analyzed the magnitude of association [expressed as odds ratio (OR)] between t-MDS/AML and i) gene expression levels in PBSC at the pre-aHCT time point; ii) gene expression levels in BM at time of t-MDS/AML; and iii) change of expression of individual genes from PBSC to time of t-MDS/AML. False discovery rate (FDR) was applied to adjust for multiple testing. Gene set enrichment analysis (GSEA) was performed on ranked lists of genes differentially expressed between cases and controls. Where multiple significant gene sets were related to each other, analysis was performed to identify a subset of common enriched genes. Average gene expression was calculated for each set and heatmaps plotted to show the contrasts between cases and controls. Gene Ontology (GO) and pathway analysis was performed using DAVID 2008 and Ingenuity IPA 7.5 respectively, retaining genes with z-scores M-bM-^IM-%1.8 or M-bM-^IM-$-1.8, and M-bM-^IM-%1.5-fold change in OR between cases and controls. The association between gene expression in the PBSC product and subsequent development of t-MDS/AML identified in the training set was validated in an independent test set of 36 PBSC sample procured from patients who developed t-MDS/AML after aHCT (16 cases) or did not (20 controls). Pre-processing, normalization and filtering procedures for the test set were identical to the training set. Differential expression between cases and controls was analyzed using CLM. GSEA analysis was performed on the ranked list of differentially expressed genes. Prediction analysis of microarray (PAM) was used to derive a prognostic gene signature from the training set to classify patients as case or control. PAM uses the M-bM-^@M-^\nearest shrunken centroidM-bM-^@M-^] approach and 10-fold cross-validation to select a parsimonious gene expression signature that can classify samples with minimal misclassification. PAM was applied to genes common to both datasets. Based on the misclassification error in cross-validation, a 63-gene signature was selected for prediction using the test data.
Project description:The development of therapeutic anticancer vaccines calls for the identification of tumor-specific antigens (TSAs). Though a combination of four cutting-edge proteogenomic approaches, we performed a deep exploration of the MHC-I presented peptides (MAPs) of 19 acute myeloid leukemia (AML) patients and identified various TSAs that could serve for the design of an anti-AML vaccine.
Project description:An influenza A microarray was used to type influenza A H1N1 specimens collected in Washington State and the results compared with identification by both culture and real time RT PCR. The microarray was more sensitive than conventional influenza testing. Cluster analysis of the microarray data discriminated specimens into distinct clades. Specimens from two pediatric decedents formed a unique clade upon H1 analysis. Keywords: Comparative genome study; Influenza A strains; Subtype H1N1 23 influenza A H1N1 specimens collected in Washington State were subtyped by microarray and data was compared with identification by both culture and real time RT PCR.