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Biology subjects

Leahy, C. I.

Publications and source records attributed to Leahy, C. I..

3 recordsLinked to original sources

The spatial landscape of infectious mononucleosis tonsils

Primary Epstein-Barr virus (EBV) infection remains incompletely understood, particularly in relation to the nature of in vivo latency patterns and their influence on the immune microenvironment. Here, we present the first multiomic single-cell spatial atlas of palatine tonsils from individuals with infectious mononucleosis (IM). We identify rare EBV infection of epithelial cells, challenging the prevailing assumption that primary infection is restricted to B- and T-cells. Moreover, our detailed analysis suggests a spatiotemporal transition of EBV latency programs, with distinct viral gene expression patterns corresponding to specific tissue microenvironments-a dynamic process previously inferred but not directly mapped in human tissues. We found that cells expressing the EBV-encoded protein LMP1 form an immunosuppressive niche that is rich in IDO1+PDL1+ macrophages and relatively depleted of T-cells. Furthermore, the T-cells that do infiltrate LMP1+ regions exhibit signatures consistent with an activated and cytotoxic phenotype, providing new insights into how LMP1 shapes immune evasion. Taken together, our data redefine the spatial and functional organisation of primary EBV infection, integrating latency plasticity, epithelial tropism, and microenvironmental immunosuppression into a unified framework, as well as providing a data-rich framework for understanding viral persistence and immune evasion.

immunology↗

CellMAPS: A no-code model-based customisable multiplex image analysis workflow

Although multiplex imaging allows simultaneous mapping of complex tissue architectures and cellular phenotypes, the dearth of user-friendly robust image analysis workflows remains a significant limitation to its widespread use, restricting multiplex imaging to laboratories with image analysis expertise. Here, we introduce a no-code model-based customisable suite, CellMAPS, which allows both image processing and spatial analyses by non-specialists. We also developed new tools for tissue de-arraying, image normalisation and cell segmentation to increase usability and reduce analysis subjectivity. We have also introduce new spatial analysis tools for the partition of tissue architectures and cellular microenvironments. We demonstrate the capabilities of CellMAPS in various diseases captured using different multiplex imaging platforms. Overall, CellMAPS provides a platform for inexperienced laboratories to implement multiplex imaging and complex spatial analyses, which ultimately should lead to the broader adoption of these technologies in the biomedical field.

bioinformatics↗

Multi-omic spatial profiling reveals the unique virus-driven immune landscape of COVID-19 placentitis

COVID-19 placentitis, a rare complication of maternal SARS-CoV-2 infection, only shows detectable virus in the placenta of a subset of cases. We provide a deep multi-omic spatial characterisation of placentitis from obstetrically complicated maternal COVID-19 infection. We found that SARS-CoV-2 infected placentas have a distinct transcriptional and immunopathological signature. This signature overlaps with virus-negative cases supporting a common viral aetiology. An inverse correlation between viral load and disease duration suggests viral clearance over time. Quantitative spatial analyses revealed a unique microenvironment surrounding virus-infected trophoblasts characterised by PDL1-expressing macrophages, T-cell exclusion, and interferon blunting. In contrast to uninfected mothers, ACE2 was localised to the maternal side of the placental trophoblast layer of almost all mothers with placental SARS-CoV-2 infection, which may explain variable susceptibility to placental infection. Our results demonstrate a pivotal role for direct placental SARS-CoV-2 infection in driving the unique immunopathology of COVID-19 placentitis. Graphical Abstract O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY

immunology↗