Biology subjects

Devlin, S.

Publications and source records attributed to Devlin, S..

3 recordsLinked to original sources

bioRxiv2025

SIMple: A fibre-based platform for accessible structured illumination microscopy

Structured illumination microscopy can be used to achieve optical sectioning and super resolution in fluorescence images, reducing out-of-focus light and increasing the resolution beyond the diffraction limit, without the need for specialised detection optics. However, the complex illumination path is difficult to build and align. We present an illumination path based on fibre-optic components for both splitting and phase-shifting the illumination light. This enables a SIMple and compact "Plug&Play" modality which substantially reduces the time and alignment required when adding the optics to an existing widefield instrument. The system is capable of optical sectioning imaging at camera-limited frame-rates using multiple excitation wavelengths simultaneously, as demonstrated by imaging fixed and live biological samples at 561 and 491 nm. Super-resolution imaging of fixed samples on a very compact, self-contained microscope is also demonstrated: illumination is coupled in by fibre to a lightweight frame with dimensions of just 300 x 450 x 300 mm3, enabling easy transportation and use in laboratories with limited space. Characterisation of the system using bead analysis shows a resolution of 168 and 172 nm at 491 and 561 nm, respectively, an improvement by a factor of 1.91 and 1.92 compared to widefield, with a field of view of 100 x 100 {micro}m2.

bioengineering↗

bioRxiv2022

Evidence of a novel viral membranefusion mechanism shared by theHepaci, Pegi and Pestiviruses

Enveloped viruses encode specialised glycoproteins that mediate fusion of viral and host membranes. Discovery and understanding of the molecular mechanisms of fusion has been achieved through structural analyses of glycoproteins from many different viruses, and yet the fusion mechanisms of some viral genera remain unknown. We have employed systematic genome annotation and AlphaFold modelling to predict the structures of the E1E2 glycoproteins from sixty viral species in the Hepaci, Pegi and Pestivirus genera. Whilst the predicted structure of E2 varied widely, E1 exhibited a very consistent fold across genera, despite little or no homology at the sequence level. Critically, the structure of E1 is unlike any other known viral glycoprotein. This is the first evidence that the Hepaci, Pegi and Pestiviruses possess a common and novel membrane fusion mechanism. Comparison of E1E2 models from various species reveals recurrent features that are likely to be mechanistically important and sheds light on the evolution of membrane fusion in these viral genera. These findings provide new fundamental understanding of viral membrane fusion and are relevant to structure-guided vaccinology.

microbiology↗

bioRxiv2018

Bile acid metabolites control Th17 and Treg cell differentiation

Bile acids are abundantly present in the mammalian gut, where they undergo bacteria-mediated transformation, generating a large pool of bioactive molecules. While they have been shown to affect host metabolism, cancer progression and innate immunity, it is unknown whether bile acids affect the function of adaptive immune cells such as T cells expressing IL-17a (Th17 cells) and regulatory T cells (Tregs) that mediate inflammatory and anti-inflammatory responses, respectively. By screening a small-molecule library primarily composed of bile acid metabolites, we identified two distinct derivatives of lithocholic acid (LCA), 3-oxoLCA and isoalloLCA, as specific regulators of Th17 and Treg cells. While 3-oxoLCA inhibited Th17 cell differentiation by directly binding to its key transcription factor ROR{gamma}t (retinoid-related orphan receptor {gamma} t), isoalloLCA enhanced differentiation of Tregs through mitochondrial-dependent metabolic changes, leading to an increased expression of Foxp3. IsoalloLCA-dependent Treg enhancement required an intronic Foxp3 enhancer, the conserved noncoding sequence 3 (CNS3), which acts as an epigenetic switch that confers a poised state to the Foxp3 promoter. Lastly, oral administration of 3-oxoLCA and isoalloLCA to mice led to reduced Th17 and increased Treg cell differentiation in the intestinal lamina propria. Altogether, our data suggest novel mechanisms by which bile acid metabolites control host immune responses by directly modulating the Th17 and Treg balance.

immunology↗