Biology subjects

Morrison, A. I.

Publications and source records attributed to Morrison, A. I..

3 recordsLinked to original sources

bioRxiv2025

Integration of lymphatic vasculature to a human lymph node-on-chip enhances physiological immune properties

To study systemic human innate and adaptive immune responses in detail, competent in vitro lymph node (LN) models with LN stromal cells (LNSCs) are required to recapitulate the physiological microenvironment. The multicellular organisation of LNs possesses a challenge for designing such microphysiological systems (MPS), particularly with the structural complexity of LNs and the lymphatic vasculature. Here, we established an organotypic LN model with integrated lymphatics in an organ-on-chip (OoC) platform containing a printed sacrificial structure, and studied the influence of a perfused lymphatic endothelial cell (LEC)-lined channel on the LN-on-chip microenvironment. Upon one-week of culture under lymphatic flow, LECs lined the tubular structure forming a lymphatic vessel through the LN model, and stable metabolic conditions within the LN-on-chip were confirmed. Interestingly, LECs in the LN-on-chip displayed the phenotype found in human LNs with upregulation of LEC-specific LN markers, such as atypical chemokine receptor 4 (ACKR4). The presence of the LEC-lined perfused vessel in the LN-on-chip resulted in the increase of native immune cells, most notably B cells, and the secretion of survival and migratory signals, namely interleukin-7 (IL-7) and CC motif chemokine ligand 21 (CCL21). Likewise, LECs promoted the abundance of immune cell clusters closer to the vessel. As such, these features represent an enhanced physiological microenvironment to allow for immune cell migration and interactions for efficient LN functioning. This approach paves the way for LN integration into multi-OoC (MOC) platforms to investigate immunological crosstalk between tissue-derived factors, immune cell trafficking and organ-specific adaptive immune responses.

bioengineering↗

bioRxiv2025

A Sacrificial 3D Printed Vessel-on-Chip Demonstrates a Versatile Approach to Model Connective Tissue Pathology

For in vitro organ models, perfused vasculature is crucial to overcome nutrient diffusion limits and to generate immunocompetent models by allowing trans-endothelial migration of immune cells in and out of the tissue. However, vasculature is often disregarded due to its complexity to generate and the necessity to integrate flow. The aim here was to overcome these limitations by combining 3D printing and multi-organ-chip technology to generate a vascularized, fibroblast-populated connective tissue matrix on-chip. A 3D printed, sacrificial, water-dissolvable structure was incorporated into a multi-organ-chip to generate hollow channels within a collagen/fibrin hydrogel. Subsequently, the channels were populated with endothelial cells. Different hydrogel concentrations of fibrin were used to mimic healthy and early granulation tissue. The vessels were perfused, and stable metabolic/viability conditions (lactate dehydrogenase, glucose, lactate) acquired after 3 days for 7 days total. In high fibrin gels, angiogenic sprouting and increased secretion of angiogenic cytokines was observed. Perfusion with monocytes revealed differentiation into macrophages and migration across the endothelium into the tissue. In conclusion, the versatile, easy method to pattern hydrogels in multi-organ-chips can serve as the basis to build the next generation of vascularized, immunocompetent human organ models, and opens new possibilities to study health and disease.

bioengineering↗

bioRxiv2023

A novel HERC4-dependent glue degrader targeting STING

Stimulator of interferon genes (STING) is a central component of the pathway sensing the presence of cytosolic nucleic acids, having a key role in type I interferon innate immune response. Localized at the endoplasmic reticulum (ER), STING becomes activated by cGAMP, which is generated by the intracellular DNA sensor cyclic GMP-AMP synthase (cGAS). Due to its critical role in physiological function and its involvement in a variety of diseases, STING has been a notable focus for drug discovery. Recent advances in drug discovery allow the targeting of proteins previously considered "un-druggable" by novel mechanism of actions. Molecular glue degraders are defined as the compounds leading targeted protein degradation (TPD) by creating novel ligase-substrate interactions. Here, we identified AK59 as a novel molecular glue degrader for STING. A genome-wide, CRISPR/Cas9 knockout screen showed that the compound-mediated degradation of STING by AK59 is compromised by the loss of HECT and RLD domain containing E3 ubiquitin protein ligase 4 (HERC4), ubiquitin-like modifier activating enzyme 5 (UBA5) and ubiquitin like modifier activating enzyme 6 (UBA6). While UBA5 and UBA6 could be the auxiliary factors for AK59 activity, our results indicate that HERC4 is the main E3 ligase for the observed degradation mechanism. Validation by individual CRISPR knockouts, co-immunoprecipitations, as well as proximity mediated reporter assays suggested that AK59 functions as a glue degrader by forming a novel interaction between STING and HERC4. Furthermore, our data reveals that AK59 was effective on the most common pathological STING mutations that cause STING-associated vasculopathy with onset in infancy (SAVI), suggesting a potential clinical application of this mechanism. Thus, these findings not only reveal a novel mechanism for compound-induced degradation of STING but also utilize HERC4 as potential E3 ligase that for TPD, enabling novel therapeutic applications.

molecular biology↗