Biology subjects

Crowe, A.

Publications and source records attributed to Crowe, A..

5 recordsLinked to original sources

bioRxiv2026

Copper chelation reprograms the tumour microenvironment to enhance immune checkpoint blockade therapy in preclinical mesothelioma

Immune checkpoint blockade provides durable benefit to only a minority of patients with pleural mesothelioma. Here we investigated whether targeting copper homeostasis could enhance anti-tumour immunity and improve responses to immune checkpoint blockade. Copper homeostasis genes were upregulated in human mesothelioma, localised to malignant and stromal cells but downregulated in lymphocytes. In murine mesothelioma, these genes were dynamically regulated during anti-CTLA-4 and anti-PD-1 therapy. Treatment with copper chelator triethylenetetramine reduced intratumoural copper, increased cytotoxic lymphocytes, and enriched inflammatory genes in tumour-infiltrating myeloid and lymphoid compartments. Furthermore, copper chelation enhanced anti-CTLA-4 and anti-PD-1 therapy in immunocompetent mesothelioma mouse models, leading to durable tumour control. Our findings identify copper homeostasis as a therapeutic vulnerability in mesothelioma and support clinical evaluation of copper depletion with first-line immune checkpoint blockade.

immunology↗

bioRxiv2025

Sexual dimorphism in the complete connectome of the Drosophila male central nervous system

Sex differences in behaviour exist across all animals, typically under strong genetic regulation. In Drosophila, fruitless/doublesex transcription factors can identify dimorphic neurons but their organisation into functional circuits remains unclear. We present the connectome of the entire Drosophila male central nervous system. This contains 166,691 neurons spanning the brain and nerve cord, fully proofread and annotated including fruitless/doublesex expression and 11,691 types. We provide the first comprehensive comparison between male and female brain connectomes to synaptic resolution, finding 7,205 isomorphic, 114 dimorphic, 262 male-specific and 69 female-specific types. This resource enables analysis of full sensory-to-motor circuits underlying complex behaviours and the impact of dimorphic elements. Sex-specific/dimorphic neurons are concentrated in higher brain centres while the sensory and motor periphery are largely isomorphic. Within higher centres, male-specific connections are organised into hotspots defined by male-specific neurons or arbours. Numerous circuit switches reroute sensory information to form antagonistic circuits controlling opposing behaviours.

neuroscience↗

bioRxiv2021

Structure, dynamics, and inhibition of Staphylococcus aureus m1A22-tRNA methyltransferase

The enzyme m1A22-tRNA methyltransferase (TrmK) catalyses the transfer of a methyl group from SAM to the N1 of adenine 22 in tRNAs. TrmK is essential for Staphylococcus aureus survival during infection, but has no homologue in mammals, making it a promising target for antibiotic development. Here we describe the structural and functional characterisation of S. aureus TrmK. Crystal structures are reported for S. aureus TrmK apoenzyme and in complexes with SAM and SAH. Isothermal titration calorimetry showed that SAM binds to the enzyme with favourable but modest enthalpic and entropic contributions, whereas SAH binding leads to an entropic penalty compensated by a large favourable enthalpic contribution. Molecular dynamics simulations point to specific motions of the C-terminal domain being altered by SAM binding, which might have implications for tRNA recruitment. Activity assays for S. aureus TrmK-catalysed methylation of WT and position 22 mutants of tRNALeu demonstrate that the enzyme requires an adenine at position 22 of the tRNA. Intriguingly, a small RNA hairpin of 18 nucleotides is methylated by TrmK depending on the position of the adenine. In-silico screening of compounds suggested plumbagin as a potential inhibitor of TrmK, which was confirmed by activity measurements. Furthermore, LC-MS indicated the protein was covalently modified by one equivalent of the inhibitor, and proteolytic digestion coupled with LC-MS identified Cys92, in the vicinity of the SAM-binding site, as the sole residue modified. These results these results identify a cryptic binding pocket of S. aureus TrmK and lay the foundation for future structure-based drug discovery.

biochemistry↗

bioRxiv2020

BioSkills Guide: Development and National Validation of a Tool for Interpreting the Vision and Change Core Competencies

To excel in modern STEM careers, biology majors need a range of transferrable skills, yet competency development is often a relatively underdeveloped facet of the undergraduate curriculum. Here, we have elaborated the Vision and Change core competency framework into a resource called the BioSkills Guide, a set of measurable learning outcomes that can be more readily interpreted and implemented by faculty. College biology educators representing over 250 institutions, including 73 community colleges, contributed to the development and validation of the guide. Our grassroots approach during the development phase engaged over 200 educators over the course of five iterative rounds of review and revision. We then gathered evidence of the BioSkills Guides content validity using a national survey of over 400 educators. Across the 77 outcomes in the final draft, rates of respondent support for outcomes were high (74.3% - 99.6%). Our national sample included college biology educators across a range of course levels, subdisciplines of biology, and institution types. We envision the BioSkills Guide supporting a variety of applications in undergraduate biology, including backward design of individual lessons and courses, competency assessment development, curriculum mapping and planning, and resource development for less well-defined competencies.

scientific communication and education↗

bioRxiv2017

Dominance of ST131 Escherichia coli carrying blaCTX-M in patients with bloodstream infections caused by cephalosporin-resistant strains in Australia, New Zealand and Singapore: whole genome analysis of isolates from a randomised trial

Synopsis/AbstractO_ST_ABSObjectivesC_ST_ABSTo characterise multi-drug resistant Escherichia coli isolated from patients in Australia, New Zealand and Singapore with bloodstream infection (BSI).\n\nMethodsWe prospectively collected third-generation cephalosporin resistant (3GC-R) E. coli from blood cultures obtained from patients enrolled in a randomised controlled trial. Whole genome sequencing was used to characterise antibiotic resistance genes, sequence types (STs), plasmids and phylogenetic relationships. Antibiotic susceptibility was determined using disk diffusion and Etest.\n\nResultsA total of 70 E. coli were included, of which the majority were ST131 (61.4%). BSI was most frequently from a urinary source (69.6%), community-associated (62.9%) and in older patients (median age 71 years [IQR 64-81]). The median Pitt bacteraemia score at presentation was 1 (IQR 0-2, range 0-3) and ICU admission was infrequent (3.1%). ST131 possessed significantly more acquired resistance genes than non-ST131 (p=0.003). Clade C1/C2 ST131 predominated (30.2% and 53.5% of all ST131 respectively) and these were all resistant to ciprofloxacin. All clade A ST131 were community-associated. The predominant ESBL types were blaCTX-M (78.6% of isolates) and were strongly associated with ST131, with the majority blaCTX-M-15. Clade C1 was associated with blaCTX-M-14 and blaCTX-M-27, whereas blaCTX-M-15 predominated in clade C2. Plasmid-mediated AmpC (p-AmpC) genes (mainly blaCMY-2) were also frequent (17.1%) but were more common with non-ST131 strains (p< 0.001). The majority of plasmid replicon types were IncF.\n\nConclusionsIn a prospective collection of 3GC-R E. coli causing BSI in the Australasian region, community-associated Clade C1/C2 ST131 predominate in association with blaCTX-M ESBLs, although a significant proportion of non-ST131 strains carried blaCMY-2.

microbiology↗