Biology subjects

Braithwaite, A. T.

Publications and source records attributed to Braithwaite, A. T..

2 recordsLinked to original sources

bioRxiv2025

Intra- and intercellular immune responses across diverse in vitro stimuli and inflammatory disease

In vitro stimulation of healthy human immune cells is commonly used to reproduce the immune states observed in disease, both to understand pathology and to test therapeutic approaches. However, experiments typically focus on individual cell types and stimuli and a comprehensive cellular comparison of common immunomodulators and their relevance to disease is lacking. To this end, we performed integrated single-cell transcriptomic profiling of human peripheral blood mononuclear cells treated with 11 different common in vitro stimuli, totalling over 150,000 cells from 21 immune cell subtypes. Comparative analysis of the immunomodulations revealed their shared and unique pathways, for instance stimulation via the T cell receptor (anti-CD3, CytoStimTM) and IFN- induced broad activation signatures including off-target effects across multiple cell types, whereas TNF- and LPS elicited more specific responses. Ligand-receptor interaction mapping also uncovered the common and distinct intercellular signalling pathways across stimuli. Comparing the stimuli to patient samples enabled identification of specific inflammatory disease features best replicated by each. For example, IFN- stimulation recapitulated signatures of SLE across cell types, whereas LPS induced SLE-like changes specifically within monocytes. Comparative cell-cell network analysis showed that in vitro stimuli were able to recreate some, but not all, aspects of intercellular interactions upregulated in SLE, highlighting the limitations of these model systems. This resource provides new insights into the similarities and differences of established immune stimuli at cellular resolution and facilitates appropriate use of in vitro systems to study pathways relevant to disease.

immunology↗

bioRxiv2023

Multi-organ single-cell RNA-sequencing reveals early hyperglycaemia responses that converge on fibroblast dysregulation

Diabetes causes a range of complications that can affect multiple organs. Hyperglycaemia is an important driver of diabetes-associated complications, mediated by biological processes such as dysfunction of endothelial cells, fibrosis and alterations in leukocyte number and function. Here, we dissected the transcriptional response of key cell types to hyperglycaemia across multiple tissues using single-cell RNA-seq (scRNA-seq) and identified conserved, as well as organ-specific, changes associated with diabetes complications. By studying an early timepoint of diabetes, we focus on biological processes involved in the initiation of the disease, before the later organ-specific manifestations had supervened. We used a mouse model of type 1 diabetes and performed scRNA-seq on cells isolated from the heart, kidney, liver and spleen of streptozotocin-treated and control mice after 8 weeks and assessed differences in cell abundance, gene expression, pathway activation and cell signalling across organs and within organs. In response to hyperglycaemia, endothelial cells, macrophages and monocytes displayed organ-specific transcriptional responses, whereas fibroblasts showed similar responses across organs, exhibiting a myofibroblast-like phenotype with altered metabolic gene expression and increased differentiation of myeloid-derived fibroblasts. Further, we found evidence of endothelial dysfunction in the kidney, and of endothelial to mesenchymal transition in streptozotocin-treated mouse organs. In summary, our study represents the first single-cell and multi-organ analysis of early dysfunction in type 1 diabetes-associated hyperglycaemia, and our large-scale dataset (comprising 67,611 cells) will serve as a starting point, reference atlas, and resource for further investigating the events leading to early diabetic disease.

cell biology↗