Biology subjects

Traum, D.

Publications and source records attributed to Traum, D..

5 recordsLinked to original sources

bioRxiv2026

A universal platform for simultaneous TCRα/β removal enables safer and more potent TCR therapies and autoimmune modeling

Adoptive T-cell therapies using tumour-specific T-cell receptors (TCRs) are limited by competition with endogenous receptors, which impairs efficacy and poses risks of off-target autoreactivity. Here we present a CRISPR-based platform that completely and selectively eliminates both endogenous TCR- and -{beta} chains without affecting introduced transgenic TCRs, irrespective of codon optimization. This approach achieves >90% deletion efficiency in Jurkat and primary human T cells, markedly enhancing the expression, pairing fidelity, and functional potency of transgenic receptors. Using a clinically relevant HLA-A*02:01-restricted DMF5 TCR, we show that dual TCR ablation boosts antigen-specific activation and cytotoxicity in vitro and significantly enhances tumor clearance in vivo in human immune system (HIS) mice, while preventing graft-versus-host disease (GVHD). Targeted locus amplification revealed that CRISPR-induced double-strand breaks did not alter lentiviral integration profiles, confirming genomic safety. Extending this approach to four insulin-reactive TCRs demonstrated that removal of endogenous receptors increased transduction efficiency and functional activity, with one (1E6) showing selective activation and infiltration of stem cell-derived islet grafts (SC-islets) in vivo. This study establishes a universal, safe, and scalable genome-editing platform for generating functionally precise human T cells. By integrating cancer immunotherapy and autoimmune disease modelling within a single framework, it provides a strong preclinical rationale for dual endogenous TCR removal as a route to improved specificity, safety, and therapeutic efficacy in TCR-based cell therapies.

immunology↗

bioRxiv2024

Virus-associated Inflammation Imprints an Inflammatory Profile on Long-lived Monocyte-derived Macrophages in the Human Liver

Chronic liver injury triggers the activation and recruitment of immune cells, causing antigen-independent tissue damage and liver disease progression. Tissue inflammation can reshape macrophage composition through monocyte replacement. Replacement of tissue macrophages with monocytes differentiating in an inflammatory environment can potentially imprint a phenotype that switches the liver from an immunotolerant organ to one predisposed to tissue damage. We longitudinally sampled the liver of chronic hepatitis B (CHB) patients with active liver inflammation starting antiviral therapy. Antiviral therapy suppressed viral replication and liver inflammation, which coincided with decreased myeloid activation markers. Single-cell RNA sequencing mapped peripheral inflammatory markers to a monocyte-derived macrophage population, distinct from Kupffer cells, with an inflammatory transcriptional profile. The inflammatory macrophages (iMacs) differentiated from blood monocytes and established a long-lived population. The iMacs retained their core transcriptional signature, consistent with trained immunity, resulting in a population of macrophages primed for inflammation potentially driving progressive liver disease.

immunology↗

bioRxiv2021

Alpha cell dysfunction in early type 1 diabetes

Multiple islet autoantibodies (AAb) predict type 1 diabetes (T1D) and hyperglycemia within 10 years. By contrast, T1D develops in just [~]15% of single AAb+ (generally against glutamic acid decarboxylase, GADA+) individuals; hence the single GADA+ state may represent an early stage of T1D amenable to interventions. Here, we functionally, histologically, and molecularly phenotype human islets from non-diabetic, GADA+ and T1D donors. Similar to the few remaining beta cells in T1D islets, GADA+ donor islets demonstrated a preserved insulin secretory response. By contrast, alpha cell glucagon secretion was dysregulated in both T1D and GADA+ islets with impaired glucose suppression of glucagon secretion. Single cell RNA sequencing (scRNASeq) of GADA+ alpha cells revealed distinct abnormalities in glycolysis and oxidative phosphorylation pathways and a marked downregulation of PKIB, providing a molecular basis for the loss of glucose suppression and the increased effect of IBMX observed in GADA+ donor islets. The striking observation of a distinct early defect in alpha cell function that precedes beta cell loss in T1D suggests that not only overt disease, but also the progression to T1D itself, is bihormonal in nature.

physiology↗

bioRxiv2021

Single-cell analysis of the human pancreas in type 2 diabetes using multi-spectral imaging mass cytometry

Type 2 diabetes mellitus (T2D) is a chronic age-related disorder characterized by hyperglycemia due to the failure of pancreatic beta cells to compensate for increased insulin demand, typically associated with peripheral insulin resistance. However, despite decades of research, the pathogenic mechanisms underlying T2D remain poorly defined. Imaging mass cytometry (IMC) enables multiplexed assessment of the abundance and subcellular localization of multiple proteins on the same tissue section. Herein, we utilized IMC with a panel of 34 antibodies to quantify key markers of pancreatic exocrine, islet, and immune cells as well as stromal components. We employed this panel to analyze over 2.1 million cells from 16 pancreata obtained from donors with T2D and 13 pancreata from age similar non-diabetic controls. In the T2D pancreata, we observed significant alterations in islet architecture, endocrine cell composition, and surprisingly immune cell constituents. Thus, both HLA-DR positive CD8 T cells and macrophages were enriched intra-islet in the T2D pancreas. These efforts demonstrate the utility of IMC to investigate complex events at the cellular level in order to provide new insights into the pathophysiology of T2D.

molecular biology↗

bioRxiv2021

Multiomics single-cell analysis of human pancreatic islets reveals novel cellular states in health and type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease of only partially defined etiology in which immune cells destroy insulin-producing beta cells. Using single-cell transcriptomics and an advanced analytical strategy to assess pancreatic islets of T1D, autoantibody-positive, and non-diabetic organ donors, we identified both canonical cell types and rare insulin-expressing cells with a hybrid mixture of endocrine and exocrine gene signatures within all donors. We further found elevated expression of MHC Class II pathway genes in exocrine ductal cells of T1D donors, which we confirmed through CyTOF, in situ imaging mass cytometry, and immunofluorescence analysis. Taken together, our multimodal analyses identify novel cell types and processes that may contribute to T1D immunopathogenesis and provide new cellular and molecular insights into human pancreas function.

genomics↗