Publications by authors named "Celine Posseme"

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is an autoinflammatory disorder caused by acquired somatic UBA1 mutations in hematopoietic stem cells, affecting peripheral myeloid and natural killer (NK) cells. Given the high rate of severe infections observed in VEXAS patients, we hypothesized that NK cell dysfunction contributes to this increased susceptibility. We conducted a comprehensive immune characterization of peripheral NK cells in patients with VEXAS (n=40), patients with autoinflammatory diseases without UBA1 mutations (n=22), and elderly gender-matched healthy controls (HCs) (n=16).

View Article and Find Full Text PDF

Autoantibodies against cytokines (c-aAb) have been implicated in the pathophysiology of autoimmune diseases, and a variety of infections. In addition, several independent studies have detected elevated titers of c-aAb in the circulation of healthy individuals. To further understand their impact on immune responses, we measured c-aAb against IFN-α, IFN-γ, CSF2, IL-1α, IL-6, and IL-10 in the plasma of 1000 healthy individuals of the Milieu Intérieur (MI) cohort.

View Article and Find Full Text PDF

The ICH E14/S7B Q&As highlighted the need for best practices concerning the design, execution, analysis, interpretation, and reporting of the in vivo non-rodent QT assay as a component of the integrated risk assessment to potentially support a TQT waiver or substitute. We conducted a dog telemetry study to assess the effects on QTc of six reference compounds (five positive and one negative) previously evaluated by Darpo et al. (2015) in humans.

View Article and Find Full Text PDF

Individuals differ widely in their immune responses, with age, sex and genetic factors having major roles in this inherent variability. However, the variables that drive such differences in cytokine secretion-a crucial component of the host response to immune challenges-remain poorly defined. Here we investigated 136 variables and identified smoking, cytomegalovirus latent infection and body mass index as major contributors to variability in cytokine response, with effects of comparable magnitudes with age, sex and genetics.

View Article and Find Full Text PDF
Article Synopsis
  • Recent findings show that mutations in the UBA1 gene are linked to VEXAS syndrome, an adult-onset auto-inflammatory condition, but the exact effects of these mutations are not well understood.
  • Research on a group of VEXAS patients indicates that their monocytes are not functioning properly and exhibit signs of exhaustion and altered chemokine receptor expression.
  • The study also highlights elevated levels of inflammatory cytokines in the blood of VEXAS patients, pointing to possible therapeutic targets related to inflammasome activation and inflammatory cell death.
View Article and Find Full Text PDF

Background: Gain-of-function variants of JAK1 drive a rare immune dysregulation syndrome associated with atopic dermatitis, allergy, and eosinophilia.

Objectives: This study sought to describe the clinical and immunological characteristics associated with a new gain-of-function variant of JAK1 and report the therapeutic efficacy of Janus kinase (JAK) inhibition.

Methods: The investigators identified a family affected by JAK1-associated autoinflammatory disease and performed clinical assessment and immunological monitoring on 9 patients.

View Article and Find Full Text PDF

Tuberculosis (TB) remains a major public health problem and we lack a comprehensive understanding of how () infection impacts host immune responses. We compared the induced immune response to TB antigen, BCG and IL-1β stimulation between latently infected individuals (LTBI) and active TB patients. This revealed distinct responses between TB/LTBI at transcriptomic, proteomic and metabolomic levels.

View Article and Find Full Text PDF
Article Synopsis
  • Host immunity to SARS-CoV-2 varies widely, leading to outcomes from asymptomatic infection to severe illness, with some patients showing reduced type I interferon levels before clinical deterioration.
  • Genetic mutations and neutralizing autoantibodies impacting the interferon-I pathway have been identified as risk factors for developing severe COVID-19 pneumonia.
  • In hospitalized patients, there is consistently lower responsiveness of interferon-I proteins upon immune stimulation, suggesting a potential reason for the poor effectiveness of interferon-I treatments in advanced COVID-19 cases, highlighting the need for new therapeutic approaches.
View Article and Find Full Text PDF

Natural resistance to infection is an overlooked outcome after hepatitis C virus (HCV) exposure. Between 1977 and 1979, 1,200 Rhesus D-negative Irish women were exposed to HCV-contaminated anti-D immunoglobulin. Here, we investigate why some individuals appear to resist infection despite exposure (exposed seronegative [ESN]).

View Article and Find Full Text PDF

Most of the organs of the digestive tract comprise secretory epithelia that require specialized molecular machines to achieve their functions. As such anterior gradient (AGR) proteins, which comprise AGR1, AGR2, and AGR3, belong to the protein disulfide isomerase family, and are involved in secretory and transmembrane protein biogenesis in the endoplasmic reticulum. They are generally expressed in epithelial cells with high levels in most of the digestive tract epithelia.

View Article and Find Full Text PDF
Article Synopsis
  • The IL-12 family consists of unique cytokines that have various functional roles and the study found a dual response of IL-12p70 to LPS stimulation in healthy individuals.
  • Interferon β (IFNβ) plays a crucial role in promoting IL-12p70 production, and this effect is linked to the levels and activation of circulating monocytes.
  • The findings are clinically relevant, showing that patients with severe SARS-CoV-2 or chronic hepatitis C infections exhibit diminished IFNβ-IL-12p70 responses, which improve once the viral infection is resolved.
View Article and Find Full Text PDF

Objective: Primary Sjögren's syndrome (SS) is the second most frequent systemic autoimmune disease, affecting 0.1% of the general population. To characterize the molecular and clinical variabilities among patients with primary SS, we integrated transcriptomic, proteomic, cellular, and genetic data with clinical phenotypes in a cohort of 351 patients with primary SS.

View Article and Find Full Text PDF

The Rhesus D antigen (RhD) has been associated with susceptibility to several viral infections. Reports suggest that RhD-negative individuals are better protected against infectious diseases and have overall better health. However, potential mechanisms contributing to these associations have not yet been defined.

View Article and Find Full Text PDF

Both innate and adaptive lymphocytes have critical roles in mucosal defense that contain commensal microbial communities and protect against pathogen invasion. Here we characterize mucosal immunity in patients with severe combined immunodeficiency (SCID) receiving hematopoietic stem cell transplantation (HSCT) with or without myeloablation. We confirmed that pretransplant conditioning had an impact on innate (natural killer and innate lymphoid cells) and adaptive (B and T cells) lymphocyte reconstitution in these patients with SCID and now show that this further extends to generation of T helper 2 and type 2 cytotoxic T cells.

View Article and Find Full Text PDF

Type I interferons are essential for host response to viral infections, while dysregulation of their response can result in autoinflammation or autoimmunity. Among IFNα (alpha) responses, 13 subtypes exist that signal through the same receptor, but have been reported to have different effector functions. However, the lack of available tools for discriminating these closely related subtypes, in particular at the protein level, has restricted the study of their differential roles in disease.

View Article and Find Full Text PDF

Desmoplakin (DSP) and Desmoglein 1 (DSG1) variants result in skin barrier defects leading to erythroderma, palmoplantar keratoderma and variable [AQ4] other features. Some DSG1 variant carriers present with SAM syndrome (Severe dermatitis, multiple Allergies, Metabolic wasting) and a SAM-like phenotype has been reported in 4 subjects with different heterozygous DSP variants. We report here a patient with a novel DSP spectrin region (SR) 6 variant c.

View Article and Find Full Text PDF

The contribution of host genetic and nongenetic factors to immunological differences in humans remains largely undefined. Here, we generated bacterial-, fungal-, and viral-induced immune transcriptional profiles in an age- and sex-balanced cohort of 1,000 healthy individuals and searched for the determinants of immune response variation. We found that age and sex affected the transcriptional response of most immune-related genes, with age effects being more stimulus-specific relative to sex effects, which were largely shared across conditions.

View Article and Find Full Text PDF

Systems approaches for the study of immune signaling pathways have been traditionally based on purified cells or cultured lines. However, in vivo responses involve the coordinated action of multiple cell types, which interact to establish an inflammatory microenvironment. We employed standardized whole-blood stimulation systems to test the hypothesis that responses to Toll-like receptor ligands or whole microbes can be defined by the transcriptional signatures of key cytokines.

View Article and Find Full Text PDF