Infection

New zebrafish model should speed research on parasite that causes toxoplasmosis

New zebrafish model should speed research on parasite that causes toxoplasmosis

Researchers at Oregon State University have found a method to speed the search for new therapies to treat toxoplasmosis – by successfully infecting zebrafish with Toxoplasma gondii.

The findings were just published in the Journal of Fish Diseases, in work supported by the Tartar Foundation and the National Institutes of Health.

  1. gondii, a protozoan parasite, can infect a wide range of hosts, and is one of the most prevalent parasites in the world. It has been estimated to infect about one-third of the human race. Treatment can be difficult because parasites often have biologic similarities to the hosts they infect.

Zebrafish have been found in recent years to be an excellent model for biomedical research because they reproduce rapidly, bear many similarities to human genetics and biological systems, and can be used in “high throughput” technologies to literally test hundreds of compounds in a fairly short period of time.

“This advance may provide a very efficient tool for the discovery of new therapies for this parasitic infection,” said Justin Sanders, an OSU postdoctoral fellow and lead author on the study. “With it we should be able to more easily screen a large library of compounds, at much less expense, and look at things that are unknown or have never been considered as a possible treatment.”

Although it infects many animals, T. gondii infection has never been observed prior to this in fish. But the OSU researchers found that by raising the temperature of the water in which zebrafish lived to a warmer-than-normal 98.6 degrees, or the temperature of a human body, they could become infected with the parasite but also survive.

T. gondii affects a wide range of mammals and birds, and cats are actually one of the most routine hosts,” said Michael Kent, a professor of microbiology in the OSU College of Science. “It can cause congenital defects, which is one reason that pregnant women are told not to clean the catbox. Many people become infected for life. These chronic infections can cause serious eye disease and can be fatal to people with weakened immune systems.

“New therapies would clearly be of value, and now we have a better way to find them,” he said.

This work was done in collaboration with researchers from the University of Chicago, Albert Einstein College of Medicine, and the U.S. Department of Agriculture.

The study this story is based on is available online: http://onlinelibrary.wiley.com/doi/10.1111/jfd.12393/full

Original article: http://oregonstate.edu/ua/ncs/archives/2015/may/new-zebrafish-model-should-speed-research-parasite-causes-toxoplasmosis

Seasonal Flu Outbreaks

UMaine Study the First to Establish Zebrafish as Model for Studying the Influenza Virus

University of Maine. (2014) UMaine Study the First to Establish as Model for Studying the Influenza Virus. UMaine News.

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In the ongoing struggle to prevent and manage seasonal flu outbreaks, animal models of influenza infection are essential to gaining better understanding of innate immune response and screening for new drugs.

“A zebrafish model of IAV infection will provide a powerful new tool in the search for new ways to prevent and treat influenza,” according to the researchers, who published their findings in the journal Disease Models & Mechanisms.

In the ongoing struggle to prevent and manage seasonal flu outbreaks, animal models of influenza infection are essential to gaining better understanding of innate immune response and screening for new drugs. A research team led by University of Maine scientists has shown that two strains of human influenza A virus (IAV) can infect live zebrafish embryos, and that treatment with an anti-influenza compound reduces mortality.

It is the first study establishing the zebrafish as a model for investigating IAV infection.

The research team is led by professor Carol Kim and graduate student Kristin Gabor of UMaine’s Graduate School of Biomedical Sciences and Engineering, and includes four other UMaine researchers and one from Ghent University.

Most studies of viral pathogens that can infect zebrafish have been limited to fish-specific viruses. However, in recent years, four human viral illnesses have been reported to be modeled in zebrafish — herpes simplex, hepatitis C and chikungunya and now influenza A.

For studies of flu virus infection, the researchers focused on specific sialic acids and cytokines comparable in zebrafish embryos and humans. For these studies the zebrafish embryos also were kept in a temperature range comparable to the human respiratory tract (77 to 91.4 degrees F).

“The transparent zebrafish embryo allows researchers to visualize, track and image fluorescently labeled components of the immune response system in vivo, making it ideal for immunological research,” said Kim, a UMaine microbiologist and vice president for research and graduate school dean, writing earlier this year in the journal Developmental and Comparative Immunology

In addition, the antiviral drug Zanamivir, known for being effective in treating influenza A and B in humans, was tested in vivo and was found to reduce IAV infection.

The researchers note that studies of IAV infection in adult zebrafish have the potential to provide valuable insights into infectious disease processes, particularly in understanding adaptive immune response and vaccine efficacy. This is critically important in light of the rapidly developing resistance of the influenza virus to drug therapies.

“This zebrafish embryo model of IAV infection will be an important resource for dissecting molecular mechanisms of host-pathogen interactions in vivo, as well as for identifying new antiviral therapies,” write the researchers.

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