From A to Z(ebrafish) with Joana Rocha Pereira

There are plenty of fish in the sea (or in this case, freshwater), but what about in virology? Recently, we connected with Leuven-based researcher that is currently using zebrafish as a new model to study virus replication and intestinal enteroids. Meet Joana Rocha Pereira, Assistant Professor at the Rega Institute in Leuven, Belgium, and partner of GUTVIBRATIONS.

Meet Joana Rocha Pereira

Prior to joining GUTVIBRATIONS, Joana obtained her PhD at the University of Porto (Portugal) in 2013. Her research focuses on understanding viral replication and identifying small molecule in antivirals, and she has established a collection of in vitro assays and small animal models of viral replication for several viruses, including human noroviruses (HuNoV). For multiple years, Joana worked on antiviral research for noroviruses while using the mouse norovirus as a surrogate.

During her training on valorization and exploitation of research at KU Leuven, Joana was introduced to another researcher who was working with zebrafish. As a part of her training, Joana needed to come up with a research idea worth exploiting. Hence, the idea to use zebrafish as virus models to develop antivirals was born!

How can a fish provide answers to understanding human noroviruses?

Today, many human viruses still do not have any treatments available, despite the huge disease burden that is linked to viral diseases. It is crucial to invest in developing vaccines and antivirals, both for those viruses that are existing today and for those that might threaten us in the future. Developing antiviral therapies is not simple and requires knowledge on many aspects of their biology. With that said, Joana approaches this challenge by using innovative models to bring forward new information.

Together with her team of researchers, Joana established an in vivo model system to study HuNoV replication using zebrafish larvae. By injecting HuNoV in the yolk (food reserve) of 3-day-old zebrafish larvae, the virus can be detected in the tissues of the infected larvae by a variety of techniques including histology, ultimately indicating in which organs the virus is present. This innovative method helps cultivate human viruses to answer questions regarding their replication, tropism, and pathogenesis. “When you understand how a virus infects you and how it makes you sick, you can then develop strategies to stop viral infections” said Joana.

But there are plenty of fish in the sea, so what makes zebrafish stand out? Zebrafish are optically-transparent tropical freshwater fish that has been widely used as vertebrate models of disease. Interestingly, Zebrafish has genetic, physiologic, and pharmacologic similarities to humans. To add, zebrafish has comparable immune system to that of humans (B and T cells, macrophages, neutrophils, and a comparable set of signaling molecules and pathways), which makes them a remarkably suitable model to study human viruses, such as HuNoV.

In a publication titled “A robust human norovirus replication model in zebrafish larvae” (click here to access), Joana discloses how human noroviruses (HuNoV) replicate to high titers within zebrafish larvae. Zebrafish larvae are a part of a simple and robust replication model that facilitate studies of HuNoV biology and the development of antiviral strategies. In another publication, which is a protocol (click here to access), Joana addresses the challenges in cultivating HuNoV and described in detail how zebrafish can be used as a model in virology.

Bringing Home the Heine-Medin Award

Joana’s research has caught multiple eyes in the science industry. In 2019, her research was covered by Nature Journal. More recently, on September 16th 2021, Joana spoke at an annual meeting hosted by the European Society for Clinical Virology (ESCV). The ESCV organizes annual meetings focusing on both the clinical and basic aspects of virus research. Following her presentation, in which she explained about her research with Zebrafish, Joana received the Heine-Medin award, an prestigious ESCV award that honors scientific work that promotes the understanding of virus diseases. “It is really special considering that it recognizes my contribution to the understanding of viral diseases” Joana said.

Swimming Closer to the Development of Treatments Against Human Noroviruses

So what is the next step for Joana regarding her research with zebrafish and human noroviruses? In the lab, Joana and her team are currently working to understand the tropism and pathogenesis of noroviruses and beyond. For instance, recently, Joana and her team studied whether macrophages function as hot cells for some viruses, and thus contribute to viral dissemination or just help to control it.

By using zebrafish as an innovative model to study human noroviruses, we are one step (or dare we say, swim) closer to understanding the way human noroviruses replicate within humans, thus creating treatments against it. Would you like to read in more detail about Joana’s research? Click on the links below: