Biology subjects

Campbell, J. S.

Publications and source records attributed to Campbell, J. S..

4 recordsLinked to original sources

bioRxiv2026

Cold-Shock-Mediated Inhibition of Silk Extrusion in Galleria mellonella (Lepidoptera: Pyralidae) for Improved Handling in Infection Studies: Effects on Developmental Traits and Pathogen Susceptibility

The greater wax moth, Galleria mellonella, is an increasingly important invertebrate model for infection biology, yet silk extrusion during handling complicates larval injections and hampers survival assessment. Here, we develop and characterise a simple cold-shock method that reliably inhibits silk production without compromising larval viability. Larvae exposed to -20 {degrees}C for 10 minutes completely suppress silk extrusion with 100% survival, representing a substantial improvement over previous chilling approaches. Cold-shocked larvae successfully remained capable of completing development, although pupation and adult emergence were delayed, body weight and fecundity were reduced, and wing deformities were more common. While cold-shock did not alter silk gland morphology, spinneret structure, or fibroin gene expression, confocal imaging revealed pronounced disorganisation of F-actin and -tubulin networks within silk gland cells, indicating cytoskeletal disruption as a likely mechanism underlying silk inhibition. When challenged with Escherichia coli, cold-shocked larvae responded comparably to controls, with survival influenced primarily by feeding status. Together, these findings demonstrate that short-term cold-shock provides an efficient, reproducible, and easy implemented method for preventing silk extrusion in Galleria larvae, markedly improving handling and experimental safety while preserving their suitability as a model host for pathogen research. HighlightsO_LICold-shock at -20 {degrees}C for 10 minutes inhibits silk extrusion. C_LIO_LILarvae survive treatment with no loss of suitability for infection studies. C_LIO_LIDevelopment slows and adult weight, fecundity, and wing quality decline. C_LIO_LISilk glands stay intact; gene expression remains unchanged after cold-shock. Cytoskeletal disruption likely drives the failure of silk secretion. C_LI

microbiology↗

bioRxiv2024

PiggyBac mediated transgenesis and CRISPR/Cas9 knockout in the greater waxmoth, Galleria mellonella

The larvae of the greater waxmoth, Galleria mellonella, are gaining prominence as a versatile non-mammalian in vivo model to study host-pathogen interactions. Their ability to be maintained at 37{degrees}C, coupled with a broad susceptibility to human pathogens and a distinct melanisation response that serves as a visual indicator for larval health, positions Galleria as a powerful resource for infection research. Despite these advantages, the lack of genetic tools, such as those available for zebrafish and fruit flies, has hindered development of the full potential of Galleria as a model organism. In this study, we describe a robust methodology for generating transgenic Galleria using the PiggyBac transposon system and for precise gene knockouts via CRISPR/Cas9 technology. These advances significantly enhance the utility of Galleria in molecular research, opening the way to its widespread use as an inexpensive and ethically compatible animal model for infection biology and beyond.

bioengineering↗

bioRxiv2023

Characterising phagocytes and measuring phagocytosis from live Galleria mellonella larvae

Over the last 20 years, the larva of the greater waxmoth, Galleria mellonella, has rapidly increased in popularity as an in vivo mammalian replacement model organism for the study of human pathogens. Despite this, experimental readouts of response to infection are generally limited to observing the melanisation cascade - where the organism turns black as part of the systemic immune response - and quantifying larval death over time. As an invertebrate, Galleria harbour an innate immune system comprised of both humoral components and a repertoire of innate immune cells - termed hemocytes. Though information on subtypes of hemocytes exist, there are conflicting reports on their exact number and function. Flow cytometry has previously been used to assay Galleria hemocytes, but protocols include both centrifugation and fixation - physical methods which have the potential to affect hemocyte morphology prior to analysis. Here, we present a method for live hemocyte analysis by flow cytometry, revealing that Galleria hemocytes constitute only a single resolvable population, based on relative size or internal complexity. Using fluorescent zymosan particles, we extend our method to show that up to 80% of the Galleria hemocyte population display phagocytic capability. Finally, we demonstrate that the developed assay reliably replicates in vitro data, showing that cell wall {beta}-1,3-glucan masking by Candida albicans subverts phagocytic responses. As such, our method provides a new tool with which to rapidly assess phagocytosis and understand live infection dynamics in Galleria.

cell biology↗

bioRxiv2021

A faithful in vivo model of human macrophages in metastatic melanoma

AO_SCPLOWBSTRACTC_SCPLOWDespite recent therapeutic progress, advanced melanoma remains lethal for many patients. The composition of the immune tumor microenvironment (TME) has decisive impacts on therapy response and disease outcome. High dimensional analyses of patient samples can reveal the composition and heterogeneity of the immune TME. In particular, macrophages are known for their cancer-supportive role, but the underlying mechanisms are incompletely understood, and experimental in vivo systems are needed to test the functional properties of these cells. We characterized a humanized mouse model, reconstituted with a human immune system and a human melanoma, in which: (1) human macrophages support metastatic spread of the tumor; and (2) tumor-infiltrating macrophages have a specific transcriptional signature that faithfully represents the transcriptome of macrophages from patient melanoma samples and is associated with shorter survival. This model complements patient sample analyses, enabling the elucidation of fundamental principles in melanoma biology, and the development and evaluation of candidate therapies.

immunology↗