Biology subjects

Rooney, B.

Publications and source records attributed to Rooney, B..

5 recordsLinked to original sources

bioRxiv2025

Engineered heat-stable variants of Trypanosoma cruzi flagellar protein Tc24 enable serological detection of Chagas disease

Chagas disease, caused by the protozoan Trypanosoma cruzi, is one of the major neglected diseases globally, killing 12,000 people per year and silently infecting an estimated 7 million people worldwide. Current diagnostic methods are limited by cost, complexity and cold-chain requirements. The T. cruzi flagellar protein Tc24 is a promising antigen for serological tests but suffers of poor solubility and heat stability. Here, we computationally engineered and produced three variants of Tc24, which exhibit remarkable heat stability, up to 69{degrees}C, and express with higher solubility in E. coli compared to the wild-type protein, reducing production costs, eliminating the need for a cold chain and therefore facilitating cost-effective production and storage without refrigeration and even in lyophilised form. These variants remained remarkably stable for 70 days in solution at 25{degrees}C and successfully detected antibodies in human sera samples from Chagas disease patients from Northern and Southern regions of Latin America, demonstrating the preservation of their antigenicity. The best-performing engineered variant was incorporated into a prototype of lateral flow test, demonstrating potential for rapid, affordable and accessible Chagas disease diagnostics in resource-limited settings.

biochemistry↗

bioRxiv2025

Mammal niches are not conserved over continental scales

Summary paragraphThe niche conservatism hypothesis states that a species relationships to habitat and climate conditions are maintained across space and time1-6. Niche stationarity is assumed when ecologists estimate species habitat needs or transfer findings across geographic regions7,8. Recent studies show that some species associations with climate and habitat vary spatially, contradicting the niche conservatism hypothesis9-18. The sources of this nonstationarity are unknown and potential mechanisms remain untested. Here we show that the environmental niches of 36 common North American mammals vary spatially across dimensions of human influence, climate, and landscape. Spatial variation is not explained by known genetic subspecies lineages. Instead, niches vary at a relatively fine spatial scale consistent with adaptations by animals to local conditions, which may be explained by genetic or behavioral changes or by unmodeled interactions with unobserved variables. Spatially varying ecology means that static niche models are not appropriate at large scales and extrapolating species niches to novel contexts may be impossible19. This complicates management decisions based on transferring findings across space and projecting species current environmental associations to responses to future change, but may provide optimism if nonstationarity represents potential for rapid evolutionary rescue.

ecology↗

bioRxiv2023

Early Alzheimer's disease pathology in human cortex is associated with a transient phase of distinct cell states

Cellular perturbations underlying Alzheimers disease are primarily studied in human postmortem samples and model organisms. Here we generated a single-nucleus atlas from a rare cohort of cortical biopsies from living individuals with varying degrees of Alzheimers disease pathology. We next performed a systematic cross-disease and cross-species integrative analysis to identify a set of cell states that are specific to early AD pathology. These changes-which we refer to as the Early Cortical Amyloid Response--were prominent in neurons, wherein we identified a transient state of hyperactivity preceding loss of excitatory neurons, which correlated with the selective loss of layer 1 inhibitory neurons. Microglia overexpressing neuroinflammatory-related processes also expanded as AD pathological burden increased. Lastly, both oligodendrocytes and pyramidal neurons upregulated genes associated with amyloid beta production and processing during this early hyperactive phase. Our integrative analysis provides an organizing framework for targeting circuit dysfunction, neuroinflammation, and amyloid production early in AD pathogenesis.

genomics↗

bioRxiv2021

mTOR controls neurotoxic lysosome exocytosis in inflammatory reactive astrocytes

Astrocytes respond and contribute to neuroinflammation by adopting inflammatory reactive states. Although recent efforts have characterized the gene expression signatures associated with these reactive states, the cell biology underlying inflammatory reactive astrocyte phenotypes remains under-explored. Here, we used CRISPR-based screening in human iPSC-derived astrocytes to identify mTOR activation a driver of cytokine-induced endolysosomal system remodeling, manifesting as alkalinization of endolysosomal compartments, decreased autophagic flux, and increased exocytosis of certain endolysosomal cargos. Through endolysosomal proteomics, we identified and focused on one such cargo - IL-32, a disease-associated pro-inflammatory cytokine not present in rodents, whose secretion mechanism is not well understood. We found that IL-32 was partially secreted in extracellular vesicles likely to be exosomes. Furthermore, we found that IL-32 was involved in the polarization of inflammatory reactive astrocyte states, was upregulated in astrocytes in multiple sclerosis lesions, and preferentially co-localized with astrocytes in hypoxic-ischemic encephalopathy. We believe that our results advance our understanding of cell biological pathways underlying inflammatory reactive astrocyte phenotypes and identify potential therapeutic targets.

cell biology↗

bioRxiv2021

CRISPRi screens in human astrocytes elucidate regulators of distinct inflammatory reactive states

In response to central nervous system injury or disease, astrocytes become reactive, adopting context-dependent states and functional outputs. Certain inflammatory insults induce reactive astrocytes that lose homeostatic functions and gain harmful outputs through cellular pathways that are not fully understood. Here, we combined single-cell transcriptomics with CRISPRi screening in human iPSC-derived astrocytes to systematically interrogate inflammatory astrocyte reactivity. We found that autocrine-paracrine IL-6 and interferon signaling downstream of canonical NF-{kappa}B activation drove two distinct inflammatory reactive signatures - one promoted by and the other inhibited by STAT3. These signatures overlapped with those observed in other experimental contexts, including mouse models, and their markers were upregulated in the human brain in Alzheimers disease and hypoxic ischemic encephalopathy. Furthermore, we validated that these signatures were regulated by Stat3 in vivo. These results and the platform we established have the potential to guide the development of therapeutics to selectively modulate different aspects of inflammatory astrocyte reactivity.

neuroscience↗