Biology subjects

Couper, K. N.

Publications and source records attributed to Couper, K. N..

3 recordsLinked to original sources

bioRxiv2026

In vivo cellular localisation and nanoscale organisation of NLRP3 inflammasomes

The NLRP3 inflammasome is a critical regulator of inflammation, yet the localisation, organisation, and cellular sources of endogenous NLRP3 inflammasomes remain incompletely understood. Here, we generated NLRP3-mScarlet-I endogenous reporter mice enabling visualisation of NLRP3 at physiological levels in primary cells and in vivo. We show that activated NLRP3 associated with PI4P-positive membranes from multiple organelles, supporting a model where diverse membrane platforms act as a scaffold to nucleate inflammasome assembly. Super-resolution imaging revealed that NLRP3 and ASC occupy distinct nanoscale architectures within the inflammasome, with NLRP3 displaying marked structural heterogeneity and stimulus-dependent organisation. Unexpectedly, circulating monocytes and neutrophils, rather than tissue-resident populations, emerged as the dominant NLRP3-expressing cells in vivo which rapidly infiltrated tissues following systemic inflammation, highlighting an underappreciated cellular source of rapid inflammasome-driven responses. These findings reveal previously unrecognised insights into inflammasome organisation and localisation, establishing a powerful resource for investigating endogenous NLRP3 biology in health and disease.

immunology↗

bioRxiv2026

Using atorvastatin-induced vascular weakness to model brain haemorrhage in vascularised cerebral organoids

Intracerebral haemorrhage is the most severe subtype of stroke; however, pre-clinical investigation often fails to translate to the clinic. Cerebral organoids offer an adaptable, in vitro model of human brain tissue for pre-clinical investigation of disease. We recently demonstrated that the tissue can be successfully vascularised to mimic the cerebrovasculature. Cerebrovascular weakness was induced with atorvastatin to mimic damage observed in intracerebral haemorrhage and to replicate the diseases pathological features. We used atorvastatin to disrupt functional morphology in human brain microvascular endothelial cells in 2D and 3D model systems. Whole human blood was added to initiate damage to cerebral tissues. Vascularised cerebral organoids exhibited loss of vascular integrity when treated with atorvastatin. Tissue was vulnerable to injury from human whole blood, and an innate immune response was initiated, resulting in increased cell death. Here we show that vascularised cerebral organoids demonstrate a novel model platform for investigating pathology associated with human whole blood insult in intracerebral haemorrhage.

neuroscience↗

bioRxiv2020

Large Neutral Amino acid uptake and mTOR activation within CD4+ T cells coordinate Type 2 immunity and host resistance to Trichuris muris

Trichuris trichiura (whipworm) is a gastrointestinal nematode that infects approximately 465 million people worldwide. T. muris is used as a tractable model for the human whipworm. In wild type mice, infection with a high dose of T. muris eggs leads to worm expulsion, which is dependent on a CD4+Th2 response and interleukin (IL-)13 production. It is known that T cells up-regulate glycolysis and uptake of substrates upon activation. The amino acid transporter SLC7A5 has been shown necessary for activation of mTORC1, a nutrient/energy/redox sensor critical for T cell differentiation into effector cells. We found that at the peak of the immune response to T. muris, mice lacking SLC7A5 in CD4+T cells have delayed worm expulsion, lower levels of IL-13, reduced pmTOR and glycolytic rates. However, at later stages of infection IL-13 levels partially recovered alongside resistance. The critical role of CD4+T cell metabolism per se and down-stream mTOR in CD4+T cells in resistance was shown in mice lacking mTOR in CD4+T cells, that failed to expel a high dose of parasites and developed chronic infection. Our study shows that mTOR is essential for effective functioning of T cells during whipworm infection and that deletion of Slc7a5 significantly delays worm clearance.

immunology↗