Zebrafish as a genetic model for leukemia and other hematopoietic disorders

Zebrafish models of Neutropenia, Severe Combined Immunodeficiency and Leukemia have been generated in this study that recapitulates human disease. This will be useful to study disease pathogenesis and provide a platform for therapeutic development

Optimising the use of zebrafish embryos and in vitro models as alternatives to rodent testing for assessing neutrophil responses to nanomaterials

Nanomaterials (NMs) exhibit unique properties making them highly attractive for use in a variety of consumer products. There are uncertainties regarding the potential adverse effects of engineered NMs on human health, thus their safety must be thoroughly assessed to ensure the responsible exploitation of nanotechnology. Assessment of NM safety currently relies on the use of rodents, where neutrophil accumulation is commonly used as a marker of NM toxicity. However, there is an urgent need to replace, reduce, and refine the use of animals in research. Thus, zebrafish (Danio rerio) embryos and in vitro models should be utilised more widely when screening NM toxicity. In this thesis, non-protected stages of transgenic zebrafish larvae with fluorescentlylabelled neutrophils were exploited to assess inflammatory responses to NMs using two exposure methods: aqueous exposure of injured fish (using the tail fin injury model), and microinjection into the otic vesicle. Inflammatory responses were monitored at 4, 6, 8, 24 and 48 hours. In the tail fin injury model it was shown that post-injury aqueous treatment with silver (Ag) and zinc oxide (ZnO) NMs stimulated an enhanced and sustained neutrophilic inflammatory response. Following microinjection, Ag NMs stimulated a neutrophilic inflammatory response at the otic vesicle. These results show that the zebrafish larvae can be used to quickly determine the pro-inflammatory effects of NMs. An in vitro investigation of neutrophil responses was performed to investigate the migration of primary human neutrophils and a neutrophil-like cell line (HL-60) towards conditioned medium (CM) generated by lung epithelial cells (A549 cells) exposed to Ag NMs. It was found that the migration of neutrophils was not observed in response to CM. These results highlight that further optimisation is required to improve upon existing neutrophil in vitro models, in order to fully assess the pro-inflammatory effects of NMs in vitro. Overall, the results demonstrate that zebrafish larvae are a suitable alternative model for assessing NM toxicity, and that they should be prioritised for use by the wider scientific community for assessing chemical safety (e.g. NMs, pathogens, pharmaceuticals). In addition, the responses of neutrophils in vitro can be studied to quickly assess NM toxicity. The more widespread use of such alternative, non-rodent models will make nanotoxicology testing quicker, cheaper, and more ethical