Biology subjects

Isles, H.

Publications and source records attributed to Isles, H..

3 recordsLinked to original sources

bioRxiv2021

A zebrafish reporter line reveals immune and neuronal expression of endogenous retrovirus.

Endogenous retroviruses (ERVs) are fossils left in our genome from retrovirus infections of the past. Their sequences are part of every vertebrate genome and their random integrations are thought to have contributed to evolution. Although ERVs are mainly kept silenced by the host genome, they are found activated in multiple disease states such as auto-inflammatory disorders and neurological diseases. What makes defining their role in health and diseases challenging is the numerous copies in mammalian genomes and the lack of tools to study them. In this study, we identified 8 copies of the zebrafish endogenous retrovirus (zferv). We created and characterised the first in vivo ERV reporter line in any species. Using a combination of live imaging, flow cytometry and single cell RNA sequencing, we mapped zferv expression to early T cells and neurons. Thus, this new tool identified tissues expressing ERV in zebrafish, highlighting a potential role of ERV during brain development and strengthening the hypothesis that ERV play a role in immunity and neurological diseases. This transgenic line is therefore a suitable tool to study the function of ERV in health and diseases.

cell biology↗

bioRxiv2019

Inhibition of ErbB kinase signalling promotes resolution of neutrophilic inflammation

Neutrophilic inflammation with prolonged neutrophil survival is common to many inflammatory conditions, including chronic obstructive pulmonary disease (COPD). There are few specific therapies that reverse neutrophilic inflammation, but uncovering mechanisms regulating neutrophil survival is likely to identify novel therapeutic targets. Screening of 367 kinase inhibitors in human neutrophils and a zebrafish tail fin injury model identified ErbBs as common targets of compounds that accelerated inflammation resolution. The ErbB inhibitors gefitinib, CP-724714, erbstatin and tyrphostin AG825 significantly accelerated apoptosis of human neutrophils, including neutrophils from people with COPD. Neutrophil apoptosis was also increased in Tyrphostin AG825 treated-zebrafish in vivo. Tyrphostin AG825 decreased peritoneal inflammation in zymosan-treated mice, and increased lung neutrophil apoptosis and macrophage efferocytosis in a murine acute lung injury model. Tyrphostin AG825 and knockdown of egfra and erbb2 by CRISPR/Cas9 reduced inflammation in zebrafish. Our work shows that inhibitors of ErbB kinases have therapeutic potential in neutrophilic inflammatory disease.

immunology↗

bioRxiv2019

Non-apoptotic pioneer neutrophils initiate an endogenous swarming response in a zebrafish tissue injury model

Neutrophils are rapidly recruited to inflammatory sites where they coordinate their migration to form clusters, a process termed neutrophil swarming. The factors which modulate neutrophil swarming during its early stages are not fully understood, requiring the development of new in vivo models. Using transgenic zebrafish larvae to study endogenous neutrophil migration in a tissue damage model, we demonstrate that neutrophil swarming is a conserved process in zebrafish immunity, sharing essential features with mammalian systems. We show that neutrophil swarms initially develop around a pioneer neutrophil, in a three-phase sequence of events. By adopting a high-resolution confocal microscopy approach, we observed the release of cell fragments by early swarming neutrophils. We developed a neutrophil specific histone H2A transgenic reporter line TgBAC(mpx:GFP)i114;Tg(lyz:H2A-mCherry)sh530 to study neutrophil extracellular traps (NETs), and found that endogenous neutrophils recruited to sites of tissue damage released NETs at the start of the swarming process. The optical transparency achieved using the zebrafish model has provided some of the highest resolution imaging of NET release in vivo to date. Using a combination of transgenic reporter lines and DNA intercalating agents, we demonstrate that pioneer neutrophils release extracellular traps during the swarming response, suggesting that cell death signalling via NETosis might be important in driving the swarming response.

immunology↗