Publications by authors named "Esther Bartholomeus"

Varicella-zoster virus (VZV) is a neurotropic member of the Herpesviridae family which causes varicella in primary infection and zoster during reactivation but in rare cases can lead to severe neurological complications, such as encephalitis. To identify inborn errors of immunity (IEI) and unravel pathways involved in VZV CNS immune responses and pathogenesis, we performed whole exome sequencing on a cohort of 38 children with neurological manifestations, including VZV encephalitis, cerebellitis, or stroke. We identified a total of 46 rare potentially pathogenic variants predicted to be deleterious, including variants in innate antiviral immunity, inflammation, cell stress responses, and autophagy.

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To complement serology as a tool in public health interventions, we introduced the "celluloepidemiology" paradigm where we leveraged pathogen-specific T cell responses at a population level to advance our epidemiological understanding of infectious diseases, using SARS-CoV-2 as a model. Applying flow cytometry and machine learning on data from more than 500 individuals, we showed that the number of T cells with positive expression of functional markers not only could distinguish patients who recovered from COVID-19 from controls and pre-COVID donors but also identify previously unrecognized asymptomatic patients from mild, moderate, and severe recovered patients. The celluloepidemiology approach was uniquely capable to differentiate health care worker groups with different SARS-CoV-2 exposures from each other.

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The Wilms' tumor protein 1 (WT1) is a well-known and prioritized tumor-associated antigen expressed in numerous solid and blood tumors. Its abundance and immunogenicity have led to the development of different WT1-specific immune therapies. The driving player in these therapies, the WT1-specific T-cell receptor (TCR) repertoire, has received much less attention.

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The role of T cell receptor (TCR) diversity in infectious disease susceptibility is not well understood. We use a systems immunology approach on three cohorts of herpes zoster (HZ) patients and controls to investigate whether TCR diversity against varicella-zoster virus (VZV) influences the risk of HZ. We show that CD4 T cell TCR diversity against VZV glycoprotein E (gE) and immediate early 63 protein (IE63) after 1-week culture is more restricted in HZ patients.

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Article Synopsis
  • Discovering T-cell receptors (TCRs) for cancer therapies is often slow and costly due to the need for a lot of patient samples.
  • To improve efficiency and reduce the reliance on these samples, researchers are using prediction models to identify TCRs specific to cancer epitopes through computational methods.
  • This chapter outlines a protocol for training a prediction model using the TCRex webtool, focusing on the WT1 antigen, which is commonly overexpressed in various cancers, and provides a method to compile TCR data from healthy donors for model training.
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  • * A study analyzed genetic data from UK Biobank patients with shingles, focusing on immune responses and risk factors, uncovering significant links between susceptibility and human leukocyte antigens (HLAs).
  • * Key findings indicate that variations in the major histocompatibility complex play a crucial role in developing shingles, alongside increased immune responses related to type I interferon, offering new insights into how VZV reactivation affects the immune system.
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T-cell-based diagnostic tools identify pathogen exposure but lack differentiation between recent and historical exposures in acute infectious diseases. Here, T-cell receptor (TCR) RNA sequencing was performed on HLA-DR+/CD38+CD8+ T-cell subsets of hospitalized coronavirus disease 2019 (COVID-19) patients (n = 30) and healthy controls (n = 30; 10 of whom had previously been exposed to severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]). CDR3α and CDR3β TCR regions were clustered separately before epitope specificity annotation using a database of SARS-CoV-2-associated CDR3α and CDR3β sequences corresponding to >1000 SARS-CoV-2 epitopes.

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The immune system acts as an intricate apparatus that is dedicated to mounting a defense and ensures host survival from microbial threats. To engage this faceted immune response and provide protection against infectious diseases, vaccinations are a critical tool to be developed. However, vaccine responses are governed by levels that, when interrogated, separately only explain a fraction of the immune reaction.

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Despite the general agreement on the significance of T cells during SARS-CoV-2 infection, the clinical impact of specific and cross-reactive T-cell responses remains uncertain. Understanding this aspect could provide insights for adjusting vaccines and maintaining robust long-term protection against continuously emerging variants. To characterize CD8+ T-cell response to SARS-CoV-2 epitopes unique to the virus (SC2-unique) or shared with other coronaviruses (CoV-common), we trained a large number of T-cell receptor (TCR) - epitope recognition models for MHC-I-presented SARS-CoV-2 epitopes from publicly available data.

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Article Synopsis
  • Researchers are using human induced pluripotent stem cell (hiPSC)-derived neural models to study the interactions between the Varicella-Zoster Virus (VZV) and the immune system in neurons.
  • A new study explored whether macrophages could help activate an antiviral response in VZV-infected hiPSC-neurons, but found the macrophages were ineffective in suppressing the infection.
  • RNA sequencing results showed a weak immune response in both infected neurons and co-cultured macrophages, indicating that other immune cells, like T-cells, may be necessary for a strong antiviral response against VZV.
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  • The study focuses on improving the early diagnosis of pediatric rheumatic diseases by analyzing gene expression in blood samples and applying machine learning to develop predictive models.
  • RNA sequencing was performed on blood from children with rheumatic diseases, viral infections, and controls, leading to the development of classification models that successfully distinguished between various disease groups.
  • Results indicated that certain classifiers achieved high accuracy in differentiating rheumatic conditions, highlighting the role of innate immune responses, and suggesting blood transcriptomics combined with machine learning could aid in clinical diagnostics.
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Antigen recognition through the T cell receptor (TCR) αβ heterodimer is one of the primary determinants of the adaptive immune response. Vaccines activate naïve T cells with high specificity to expand and differentiate into memory T cells. However, antigen-specific memory CD4 T cells exist in unexposed antigen-naïve hosts.

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Auranofin (AF) is an FDA-approved antirheumatic drug with anticancer properties that acts as a thioredoxin reductase 1 (TrxR) inhibitor. The exact mechanisms through which AF targets cancer cells remain elusive. To shed light on the mode of action, this study provides an in-depth analysis on the molecular mechanisms and immunogenicity of AF-mediated cytotoxicity in the non-small cell lung cancer (NSCLC) cell line NCI-H1299 (p53 Null) and its two isogenic derivates with mutant p53 R175H or R273H accumulation.

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Thanks to the recommendation of a combined Measles/Mumps/Rubella (MMR) vaccine, like Priorix®, these childhood diseases are less common now. This is beneficial to limit the spread of these diseases and work towards their elimination. However, the measles, mumps and rubella antibody titers show a large variability in short- and long-term immunity.

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Background: Meningitis can be caused by several viruses and bacteria. Identifying the causative pathogen as quickly as possible is crucial to initiate the most optimal therapy, as acute bacterial meningitis is associated with a significant morbidity and mortality. Bacterial meningitis requires antibiotics, as opposed to enteroviral meningitis, which only requires supportive therapy.

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Article Synopsis
  • The WHO recommends hepatitis B vaccination from infancy due to its widespread presence and health risks, but existing vaccines aren’t 100% effective, leaving some individuals unprotected.
  • Using mRNA-sequencing, the study assessed immune responses after the Engerix-B vaccine, finding differences in gene expression before vaccination that correlated with antibody responses after two doses.
  • Non-responders showed an already activated immune state before vaccination and a delayed immune response afterward, suggesting that pre-existing immune conditions can affect the efficacy of hepatitis B vaccination.
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Pathogens of past and current infections have been identified directly by means of PCR or indirectly by measuring a specific immune response (e.g., antibody titration).

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Around 30% of individuals will develop herpes zoster (HZ), caused by the varicella zoster virus (VZV), during their life. While several risk factors for HZ, such as immunosuppressive therapy, are well known, the genetic and molecular components that determine the risk of otherwise healthy individuals to develop HZ are still poorly understood. We created a computational model for the Human Leukocyte Antigen (HLA-A, -B, and -C) presentation capacity of peptides derived from the VZV Immediate Early 62 (IE62) protein.

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Varicella zoster virus (VZV) typically causes chickenpox upon primary infection. In rare cases, VZV can give rise to life-threatening disease in otherwise healthy people, but the immunological basis for this remains unexplained. We report 4 cases of acute severe VZV infection affecting the central nervous system or the lungs in unrelated, otherwise healthy children who are heterozygous for rare missense mutations in POLR3A (one patient), POLR3C (one patient), or both (two patients).

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Recent increases in the number of successful cancer treatments have stimulated interest in fertility preservation strategies in women of reproductive age and in prepubertal girls. However, research on the application of such programs under clinical conditions suffers from the scarce availability of human tissue for research purposes and from concurrent relevant ethical issues. To partly address this problem, this review focuses on the possibilities of ruminant in vitro models providing additional insights into several aspects of fertility preservation, ranging from preantral follicle collection to oocyte and follicle cryopreservation, to noninvasive quality assessment, and to follicle culture.

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