Publications by authors named "Hayday A"

Multisystem inflammatory syndrome in children (MIS-C) is a rare condition following SARS-CoV-2 infection associated with intestinal manifestations. Genetic predisposition, including inborn errors of the OAS-RNAseL pathway, has been reported. We sequenced 154 MIS-C patients and utilized a novel statistical framework of gene burden analysis, "burdenMC," which identified an enrichment for rare predicted-deleterious variants in BTNL8 (OR = 4.

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The premise of cancer immunotherapy is that cancers are specifically visible to an immune system tolerized to healthy self. The promise of cancer immunotherapy is that immune effector mechanisms and immunological memory can jointly eradicate cancers and inoperable metastases and de facto vaccinate against recurrence. For some patients with hitherto incurable diseases, including metastatic melanoma, this promise is being realized by game-changing immunotherapies based on αβ T cells.

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Checkpoint inhibition (CPI), particularly that targeting the inhibitory coreceptor programmed cell death protein 1 (PD-1), has transformed oncology. Although CPI can derepress cancer (neo)antigen-specific αβ T cells that ordinarily show PD-1-dependent exhaustion, it can also be efficacious against cancers evading αβ T cell recognition. In such settings, γδ T cells have been implicated, but the functional relevance of PD-1 expression by these cells is unclear.

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Clonotypic αβ T cell responses to cargoes presented by major histocompatibility complex (MHC), MR1, or CD1 proteins underpin adaptive immunity. Those responses are mostly mediated by complementarity-determining region 3 motifs created by quasi-random T cell receptor (TCR) gene rearrangements, with diversity being highest for TCRγδ. Nonetheless, TCRγδ also displays nonclonotypic innate responsiveness following engagement of germline-encoded Vγ-specific residues by butyrophilin (BTN) or BTN-like (BTNL) proteins that uniquely mediate γδ T cell subset selection.

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Metabolic-associated fatty liver disease (MAFLD) is a spectrum of clinical manifestations ranging from benign steatosis to cirrhosis. A key event in the pathophysiology of MAFLD is the development of nonalcoholic steatohepatitis (NASH), which can potentially lead to fibrosis and hepatocellular carcinoma, but the triggers of MAFLD-associated inflammation are not well understood. We have observed that lipid accumulation in hepatocytes induces expression of ligands specific to the activating immune receptor NKG2D.

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Murine intraepithelial γδ T cells include distinct tissue-protective cells selected by epithelial butyrophilin-like (BTNL) heteromers. To determine whether this biology is conserved in humans, we characterized the colonic γδ T cell compartment, identifying a diverse repertoire that includes a phenotypically distinct subset coexpressing T cell receptor Vγ4 and the epithelium-binding integrin CD103. This subset was disproportionately diminished and dysregulated in inflammatory bowel disease, whereas on-treatment CD103γδ T cell restoration was associated with sustained inflammatory bowel disease remission.

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Article Synopsis
  • The thymus is essential for maintaining immune tolerance and defense throughout life, but it shrinks with age yet retains potential for regeneration.
  • This study examined the human thymus at a single-cell level, revealing specific epithelial cell populations that possess stem cell-like properties.
  • The identified thymic epithelial stem cells have unique characteristics and can generate multiple cell types, providing new insights into stem cell biology and potential strategies to combat thymic atrophy and related health issues.
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Background: Elicitation of allergic contact dermatitis (ACD), an inflammatory type 4 hypersensitivity disease, induces skin infiltration by polyclonal effector CD8 αβ T cells and precursors of tissue-resident memory T (T) cells. Because T have long-term potential to contribute to body-surface immunoprotection and immunopathology, their local regulation needs a fuller understanding.

Objective: We sought to investigate how T-cell maturation might be influenced by innate-like T cells pre-existing within many epithelia.

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Intraepithelial lymphocytes (IEL) expressing γδ T-cell receptors (γδTCR) play key roles in elimination of colon cancer. However, the precise mechanisms by which progressing cancer cells evade immunosurveillance by these innate T cells are unknown. Here, we investigated how loss of the Apc tumor suppressor in gut tissue could enable nascent cancer cells to escape immunosurveillance by cytotoxic γδIELs.

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Members of the Regulator of G-protein signaling (Rgs) family regulate the extent and timing of G protein signaling by increasing the GTPase activity of Gα protein subunits. The Rgs family member is one of the most up-regulated genes in tissue-resident memory (T) T cells when compared to their circulating T cell counterparts. Functionally, Rgs1 preferentially deactivates Gαq, and Gαi protein subunits and can therefore also attenuate chemokine receptor-mediated immune cell trafficking.

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Article Synopsis
  • Effective secondary responses in CD8 T cells, which are crucial for long-lasting immunity against viruses and tumors, can vary depending on the timing of antigen exposure.
  • In a study using a mouse model, researchers found that boosting CD8 T cell responses 100 days after the initial priming was more effective than boosting at 30 days, indicated by better functionality in various immune organs.
  • RNA sequencing revealed that CD8 T cells at 100 days post-priming had a quiescent but responsive state, suggesting adjustments in vaccination timing could enhance the secondary immune response.
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This study offers longitudinal insight into the impact of three SARS-CoV-2 vaccinations on humoral and cellular immunity in patients with solid cancers, patients with hematologic malignancies, and persons without cancer. For all cohorts, virus-neutralizing immunity was significantly depleted over a period of up to 9 months following the second vaccine dose, the one striking exception being IL2 production by SARS-CoV-2 antigen-specific T cells. Immunity was restored by the third vaccine dose, except in a substantial number of patients with hematologic malignancy, for whom both cancer type and treatment schedule were associated with nonresponse.

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Prolidase deficiency (PD) is a multisystem disorder caused by mutations in the PEPD gene, which encodes a ubiquitously expressed metallopeptidase essential for the hydrolysis of dipeptides containing C-terminal proline or hydroxyproline. PD typically presents in childhood with developmental delay, skin ulcers, recurrent infections, and, in some patients, autoimmune features that can mimic systemic lupus erythematosus. The basis for the autoimmune association is uncertain, but might be due to self-antigen exposure with tissue damage, or indirectly driven by chronic infection and microbial burden.

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Facing the COVID-19 pandemic, anti-SARS-CoV-2 vaccines were developed at unprecedented pace, productively exploiting contemporary fundamental research and prior art. Large-scale use of anti-SARS-CoV-2 vaccines has greatly limited severe morbidity and mortality. Protection has been correlated with high serum titres of neutralizing antibodies capable of blocking the interaction between the viral surface protein spike and the host SARS-CoV-2 receptor, ACE-2.

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Therapeutic antibodies have broad indications across diverse disease states, such as oncology, autoimmune diseases, and infectious diseases. New research continues to identify antibodies with therapeutic potential as well as methods to improve upon endogenous antibodies and to design antibodies de novo. On April 27-30, 2022, experts in antibody research across academia and industry met for the Keystone symposium "Antibodies as Drugs" to present the state-of-the-art in antibody therapeutics, repertoires and deep learning, bispecific antibodies, and engineering.

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Article Synopsis
  • This research investigates whether the emergence of specific T and B cells in response to COVID-19 disrupts the overall diversity of the immune system's cell receptor repertoire.
  • A genomic analysis of 95 individuals revealed that while there were expected increases in certain immune response sequences during SARS-CoV-2 infection, no significant issues were found in younger individuals.
  • However, older patients (over 50) showed a concerning reduction in T cell diversity, which may increase their risk for severe COVID-19 and complicate responses to emerging variants.
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COVID-19 ranges from asymptomatic through to respiratory failure and death. Although specific pre-existing conditions such as age and male sex have been associated with poor outcomes, we remain largely ignorant of the mechanisms predisposing to severe disease. In this study, the authors discovered that approximately 10% of 987 patients with life-threatening COVID-19 harbored neutralizing antibodies to Type I interferons (IFNs).

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Murine tissues harbor signature γδ T cell compartments with profound yet differential impacts on carcinogenesis. Conversely, human tissue-resident γδ cells are less well defined. In the present study, we show that human lung tissues harbor a resident Vδ1 γδ T cell population.

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  • The study investigates how γδ T cell antigen receptors (TCRs) interact with skin cells (keratinocytes) and their role in immune surveillance and normal tissue maintenance.
  • It was found that these interactions rely on a specific protein called Skint1, which helps γδ T cells to monitor the skin's normal state and respond to changes effectively.
  • Disrupting this normality sensing not only changed the T cells' characteristics but also weakened the skin's barrier, making it more vulnerable to damage from ultraviolet radiation and inflammation, which can lead to cancer.
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  • - The third edition of the Flow Cytometry Guidelines offers essential information for conducting flow cytometry experiments, covering immune cell phenotypes and functional assays in both humans and mice.
  • - It includes tables that highlight the differences between human and murine cell phenotypes, along with examples of flow cytometry applications related to autoimmune diseases, cancers, and infectious diseases.
  • - The guidelines also provide practical tips and common pitfalls to avoid, and are authored by renowned experts in the field, making it a crucial resource for researchers in both basic and clinical settings.
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Here we consider how high-content flow cytometric methodology at appropriate scale and throughput rapidly provided meaningful biological data in our recent studies of COVID-19, which we discuss in the context of other similar investigations. In our work, high-throughput flow cytometry was instrumental to identify a consensus immune signature in COVID-19 patients, and to investigate the impact of SARS-CoV-2 exposure on patients with either solid or hematological cancers. We provide here some examples of our 'holistic' approach, in which flow cytometry data generated by lymphocyte and myelomonocyte panels were integrated with other analytical metrics, including SARS-CoV-2-specific serum antibody titers, plasma cytokine/chemokine levels, and in-depth clinical annotation.

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Aims: Coronavirus disease 2019 (COVID-19) can lead to multiorgan damage. MicroRNAs (miRNAs) in blood reflect cell activation and tissue injury. We aimed to determine the association of circulating miRNAs with COVID-19 severity and 28 day intensive care unit (ICU) mortality.

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A multicolor flow cytometry panel was designed and optimized to define the following nine mouse T cell subsets: Treg (CD3 CD4 CD8 FoxP3 ), CD4 T naïve (CD3 CD4 CD8 FoxP3 CD44 CD62L ), CD4 T central memory (CD3 CD4 CD8 FoxP3 CD44 CD62L ), CD4 T effector memory (CD3 CD4 CD8 FoxP3 CD44 CD62L ), CD4 T EMRA (CD3 CD4 CD8 FoxP3 CD44 CD62L ), CD8 T naïve (CD3 CD8 CD4 CD44 CD62L ), CD8 T central memory (CD3 CD8 CD4 CD44 CD62L ), CD8 T effector memory (CD3 CD8 CD4 CD44 CD62L ), and CD8 T EMRA (CD3 CD8 CD4 CD44 CD62L ). In each T cell subset, a dual staining for Ki-67 expression and DNA content was employed to distinguish the following cell cycle phases: G (Ki67 , with 2n DNA), G (Ki67 , with 2n DNA), and S-G /M (Ki67 , with 2n < DNA ≤ 4n). This panel was established for the analysis of mouse (C57BL/6J) spleen.

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