Holden T Maecker

Stanford University, Stanford, California, United States

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Publications (150)846.62 Total impact

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    Preview · Article · Nov 2015
  • S.M. Hiniker · S.A. Reddy · H.T. Maecker · S.M. Swetter · L. Shura · S.J. Knox

    No preview · Article · Nov 2015 · International journal of radiation oncology, biology, physics
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    Full-text · Article · Nov 2015
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    ABSTRACT: There is strong evidence that inflammatory mediators play a key role in the progression to heart failure in patients with systemic hypertension (HTN). The present study aimed to identify a set of cytokines that are associated with early left ventricular (LV) remodeling and dysfunction as captured by echocardiography in patients with HTN in a cross-sectional case-control study nested within the FLEMish study on ENvironment, Genes and Health Outcome. We identified three groups of participants from the cohort: normotensive subjects (normotension; n = 30), HTN with normal LV structure and function (HTN [LV-]; n = 30), and HTN with evidence of adverse LV remodeling (HTN [LV+]; n = 50). We measured cytokines using a 63-plex Luminex platform. Using partial least squares-discriminant analysis, we constructed three latent variables from the measured cytokines that explained 35%-45% of the variance between groups. We identified five common cytokines (interleukin 18, monokine induced by gamma interferon, hepatocyte growth factor, epithelial neutrophil-activating peptide 78, and vascular endothelial growth factor D) with a stable signal which had a major impact on the construction of the latent variables. Among these cytokines, after adjustment for confounders, interleukin 18 remained significantly different between HTN participants with and without LV involvement (P = .02). Moreover, granulocyte-macrophage colony-stimulating factor and leptin showed a consistent upward trend in all HTN patients compared with normotensive subjects. In conclusion, in HTN patients with LV remodeling or/and dysfunction, we identified a set of cytokines strongly associated with LV maladaptation. We also found a distinct profile of inflammatory biomarkers that characterize HTN.
    No preview · Article · Oct 2015 · Journal of the American Society of Hypertension (JASH)
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    Susan M. Hiniker · Holden T. Maecker · Susan J. Knox
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    ABSTRACT: Success with recent immunotherapies has resulted in previously unattainable response rates, as well as durable responses in diseases with historically poor prognoses. The combination of radiation therapy and immunotherapy has been a recent area of active investigation, with exciting results in a subset of patients. However, patient characteristics predictive of probable benefit from therapy and clinically meaningful biomarkers indicative of the early development of an antitumor immune response have yet to be identified. What is needed is a better way to predict which patients are likely to benefit from therapy, which would allow those patients unlikely to benefit from immunotherapy to be spared potentially futile therapies, thereby avoiding unnecessary risks of toxicity and costly treatment. Here, we summarize the early data on predictors of clinical response to immunotherapy, and to immunotherapy in combination with radiation.
    Preview · Article · Sep 2015
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    Holden T Maecker · Alexandre Harari

    Preview · Article · Sep 2015
  • Henrik E Mei · Michael D Leipold · Holden T Maecker
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    ABSTRACT: Mass cytometry has overcome limitations of fluorescent single cell cytometry by allowing for the measurement of up to currently ∼40 different parameters on a single cell level. However, the cellular proteome comprises many more potential analytes, and current mass cytometry instrumentation allows for theoretically up to 121 different mass detection channels. The labeling of specific probes with appropriate metal ions is a significant hurdle for exploiting more of mass cytometry's analytical capacity. To this end, we here describe the labeling of antibody with natural abundance or isotopically purified platinum as formulated in cisplatin and circumventing the use of chelator-loaded polymers. We confirm the utility of cisplatin-antibody-conjugates for surface, intracellular, and phosphoepitope-specific immunophenotyping, as well as for application in cell surface CD45-based barcoding. Cisplatin-labeling of antibody increases the analytical capacity of the CyTOF(®) platform by two channels based on available reagents, and has the potential to add a total of six channels for detection of specific probes, thus helping to better extend the analytical mass range of mass cytometers. © 2015 International Society for Advancement of Cytometry.
    No preview · Article · Sep 2015 · Cytometry Part A
  • Cariad Chester · Holden T Maecker
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    ABSTRACT: The advent of mass cytometry has led to an unprecedented increase in the number of analytes measured in individual cells, thereby increasing the complexity and information content of cytometric data. Although this technology is ideally suited to the detailed examination of the immune system, the applicability of the different methods for analyzing such complex data is less clear. Conventional data analysis by manual gating of cells in biaxial dot plots is often subjective, time consuming, and neglectful of much of the information contained in a highly dimensional cytometric dataset. Algorithmic data mining has the promise to eliminate these concerns, and several such tools have been applied recently to mass cytometry data. We review computational data mining tools that have been used to analyze mass cytometry data, outline their differences, and comment on their strengths and limitations. This review will help immunologists to identify suitable algorithmic tools for their particular projects. Copyright © 2015 by The American Association of Immunologists, Inc.
    No preview · Article · Aug 2015 · The Journal of Immunology
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    ABSTRACT: While many age-associated immune changes have been reported, a comprehensive set of metrics of immune aging is lacking. Here we report data from 243 healthy adults aged 40-97, for whom we measured clinical and functional parameters, serum cytokines, cytokines and gene expression in stimulated and unstimulated PBMC, PBMC phenotypes, and cytokine-stimulated pSTAT signaling in whole blood. Although highly heterogeneous across individuals, many of these assays revealed trends by age, sex, and CMV status, to greater or lesser degrees. Age, then sex and CMV status, showed the greatest impact on the immune system, as measured by the percentage of assay readouts with significant differences. An elastic net regression model could optimally predict age with 14 analytes from different assays. This reinforces the importance of multivariate analysis for defining a healthy immune system. These data provide a reference for others measuring immune parameters in older people.
    Full-text · Article · Jul 2015 · PLoS ONE
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    ABSTRACT: Many methods have been described for automated clustering analysis of complex flow cytometry data, but so far the goal to efficiently estimate multivariate densities and their modes for a moderate number of dimensions and potentially millions of data points has not been attained. We have devised a novel approach to describing modes using second order polynomial histogram estimators (SOPHE). The method divides the data into multivariate bins and determines the shape of the data in each bin based on second order polynomials, which is an efficient computation. These calculations yield local maxima and allow joining of adjacent bins to identify clusters. The use of second order polynomials also optimally uses wide bins, such that in most cases each parameter (dimension) need only be divided into 4-8 bins, again reducing computational load. We have validated this method using defined mixtures of up to 17 fluorescent beads in 16 dimensions, correctly identifying all populations in data files of 100,000 beads in <10 s, on a standard laptop. The method also correctly clustered granulocytes, lymphocytes, including standard T, B, and NK cell subsets, and monocytes in 9-color stained peripheral blood, within seconds. SOPHE successfully clustered up to 36 subsets of memory CD4 T cells using differentiation and trafficking markers, in 14-color flow analysis, and up to 65 subpopulations of PBMC in 33-dimensional CyTOF data, showing its usefulness in discovery research. SOPHE has the potential to greatly increase efficiency of analysing complex mixtures of cells in higher dimensions. © 2015 International Society for Advancement of Cytometry. © 2015 International Society for Advancement of Cytometry.
    No preview · Article · Jun 2015 · Cytometry Part A
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    ABSTRACT: The development of biomarkers for autoimmune diseases has been hampered by a lack of understanding of disease etiopathogenesis and of the mechanisms underlying the induction and maintenance of inflammation, which involves complex activation dynamics of diverse cell types. The heterogeneous nature and suboptimal clinical response to treatment observed in many autoimmune syndromes highlight the need to develop improved strategies to predict patient outcome to therapy and personalize patient care. Mass cytometry, using CyTOF®, is an advanced technology that facilitates multiparametric, phenotypic analysis of immune cells at single-cell resolution. In this review, we outline the capabilities of mass cytometry and illustrate the potential of this technology to enhance the discovery of cellular biomarkers for rheumatoid arthritis, a prototypical autoimmune disease.
    Full-text · Article · May 2015 · Arthritis research & therapy
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    Full-text · Dataset · Apr 2015
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    Full-text · Article · Apr 2015 · Immunity
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    ABSTRACT: Although stem cell therapy (SCT) is emerging as a potential treatment for patients with dilated cardiomyopathy (DCM), clinical response remains variable. Our objective is to determine whether baseline differences in circulating immune and non-immune biomarkers may help identify patients more susceptible to respond to intramyocardial injection of CD34(+) based SCT. We enrolled 37 patients with long standing DCM (LVEF <40%, NYHA class III) who underwent peripheral CD34(+) stem cell mobilization with granulocyte colony stimulating factor (G-CSF) and collection via apheresis. CD34(+) cells were labeled with (99m)Tc-hexamethylpropylene-amine oxyme ((99m)Tc-HMPAO) to allow assessment of stem cell retention at 18 hours. Response to SCT was predefined as an increase in left ventricular ejection fraction (LVEF) ≥ 5% at 3 months. The majority of patients were male (84%) with a mean LVEF of 27±7% and a median NT-proBNP level of 2774 pg/mL. Nineteen patients (51%) were responders to SCT. There was no significant difference between responders and non-responders with regards to age, sex, baseline LVEF, NT-proBNP levels or 6-minute walking distance. Using partial least squares (PLS) predictive model, we identify 9 baseline factors which were associated with both stem cell response and stem cell retention (mechanistic validation). Among the baseline factors positively associated with both clinical response and stem cell retention, we found GCSF, SDF-1, LIF, MCP-1 and MCP-3. Among baseline factors negatively associated with both clinical response and retention, we found IL12p70, FASL, ICAM-1 and GGT.A decrease in G-CSF at 3 month follow-up was also observed in responders compared to non-responders (P=0.02). If further validated, baseline immune and non-immune biomarker may help identify patients with DCM more likely to respond to CD34(+) based SCT. Copyright © 2015 Elsevier Inc. All rights reserved.
    No preview · Article · Apr 2015 · Journal of cardiac failure
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    ABSTRACT: Mass cytometry is developing as a means of multiparametric single-cell analysis. In this study, we present an approach to barcoding separate live human PBMC samples for combined preparation and acquisition on a cytometry by time of flight instrument. Using six different anti-CD45 Ab conjugates labeled with Pd104, Pd106, Pd108, Pd110, In113, and In115, respectively, we barcoded up to 20 samples with unique combinations of exactly three different CD45 Ab tags. Cell events carrying more than or less than three different tags were excluded from analyses during Boolean data deconvolution, allowing for precise sample assignment and the electronic removal of cell aggregates. Data from barcoded samples matched data from corresponding individually stained and acquired samples, at cell event recoveries similar to individual sample analyses. The approach greatly reduced technical noise and minimizes unwanted cell doublet events in mass cytometry data, and it reduces wet work and Ab consumption. It also eliminates sample-to-sample carryover and the requirement of instrument cleaning between samples, thereby effectively reducing overall instrument runtime. Hence, CD45 barcoding facilitates accuracy of mass cytometric immunophenotyping studies, thus supporting biomarker discovery efforts, and it should be applicable to fluorescence flow cytometry as well. Copyright © 2015 by The American Association of Immunologists, Inc.
    No preview · Article · Jan 2015 · The Journal of Immunology
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    ABSTRACT: There is considerable heterogeneity in immunological parameters between individuals, but its sources are largely unknown. To assess the relative contribution of heritable versus non-heritable factors, we have performed a systems-level analysis of 210 healthy twins between 8 and 82 years of age. We measured 204 different parameters, including cell population frequencies, cytokine responses, and serum proteins, and found that 77% of these are dominated (>50% of variance) and 58% almost completely determined (>80% of variance) by non-heritable influences. In addition, some of these parameters become more variable with age, suggesting the cumulative influence of environmental exposure. Similarly, the serological responses to seasonal influenza vaccination are also determined largely by non-heritable factors, likely due to repeated exposure to different strains. Lastly, in MZ twins discordant for cytomegalovirus infection, more than half of all parameters are affected. These results highlight the largely reactive and adaptive nature of the immune system in healthy individuals. Copyright © 2015 Elsevier Inc. All rights reserved.
    Full-text · Article · Jan 2015 · Cell
  • M.D. Leipold · Evan W. Newell · Holden T. Maecker
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    ABSTRACT: The standard for single-cell analysis of phenotype and function in recent decades has been fluorescence flow cytometry. Mass cytometry is a newer technology that uses heavy metal ions, rather than fluorochromes, as labels for probes such as antibodies. The binding of these ion-labeled probes to cells is quantitated by mass spectrometry. This greatly increases the number of phenotypic and functional markers that can be probed simultaneously. Here, we review topics that must be considered when adapting existing flow cytometry panels to mass cytometry analysis. We present a protocol and representative panels for surface phenotyping and intracellular cytokine staining (ICS) assays
    No preview · Article · Jan 2015
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    ABSTRACT: Inhibition of the mammalian target of rapamycin (mTOR) pathway extends life span in all species studied to date, and in mice delays the onset of age-related diseases and comorbidities. However, it is unknown if mTOR inhibition affects aging or its consequences in humans. To begin to assess the effects of mTOR inhibition on human aging-related conditions, we evaluated whether the mTOR inhibitor RAD001 ameliorated immunosenescence (the decline in immune function during aging) in elderly volunteers, as assessed by their response to influenza vaccination. RAD001 enhanced the response to the influenza vaccine by about 20% at doses that were relatively well tolerated. RAD001 also reduced the percentage of CD4 and CD8 T lymphocytes expressing the programmed death-1 (PD-1) receptor, which inhibits T cell signaling and is more highly expressed with age. These results raise the possibility that mTOR inhibition may have beneficial effects on immunosenescence in the elderly. Copyright © 2014, American Association for the Advancement of Science.
    Full-text · Article · Dec 2014 · Science translational medicine
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    ABSTRACT: Finding one or more cell populations of interest, such as those correlating to a specific disease, is critical when analyzing flow cytometry data. However, labelling of cell populations is not well defined, making it difficult to integrate the output of algorithms to external knowledge sources. We developed flowCL, a software package that performs semantic labelling of cell populations based on their surface markers and applied it to labelling of the Federation of Clinical Immunology Societies Human Immunology Project Consortium lyoplate populations as a use case. By providing automated labelling of cell populations based on their immunophenotype, flowCL allows for unambiguous and reproducible identification of standardized cell types. Code, R script and documentation are available under the Artistic 2.0 license through Bioconductor(1). rbrinkman@bccrc.ca. © The Author (2014). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
    No preview · Article · Dec 2014 · Bioinformatics
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    ABSTRACT: Arsenic has wide-ranging effects on human health and there is evidence that it alters the immune response by influencing CD4 +/CD8 + T cell ratios, IL-2 cytokine levels, and the expression of immune-response genes. We investigated the impact of in utero environmental arsenic exposure on immune development and function in newborns participating in a pregnancy cohort in New Hampshire, U.S., where arsenic levels have exceeded the current EPA maximum contaminant level of 10 μg/L. Our results showed that maternal urinary arsenic concentrations were inversely related to absolute total CD45RA + CD4 + cord blood CD69 + T cell counts (N = 116, p = 0.04) and positively associated with CD45RA + CD69- CD294 + cell counts (p = 0.01). In placental samples (N = 70), higher in utero urinary arsenic concentrations were positively associated with expression of IL1β (p = 0.03). These data provide evidence that relatively low-level arsenic exposure in utero may alter the fetal immune system and lead to immune dysregulation.
    No preview · Article · Dec 2014 · Clinical Immunology

Publication Stats

6k Citations
846.62 Total Impact Points

Institutions

  • 1996-2015
    • Stanford University
      • • Institute for Immunity, Transplantation and Infection
      • • Department of Microbiology and Immunology
      • • Department of Pediatrics
      Stanford, California, United States
    • Stanford Medicine
      • Division of Oncology
      Stanford, California, United States
  • 2009
    • Becton, Dickinson and Company (BD)
      Franklin Lakes, New Jersey, United States
  • 2004
    • Duke University
      • Department of Surgery
      Durham, North Carolina, United States
  • 1995
    • Loyola University Medical Center
      • Department of Cell Biology
      Maywood, Illinois, United States