What the Heck are Humanized Mice?

A maturing malaria parasite (purple) being studied in humanized mouse derived liver cells (green)

The phrase “Humanized Mice,” may sound strange. However, this OHSU-based discovery is in the process of saving lives.

The latest use of this technology is to aid in combatting malaria.

Here are a few of the details from an OHSU press release.

A novel human liver-chimeric mouse model developed at Oregon Health & Science University and Yecuris Corporation has made possible a research breakthrough at Seattle Biomedical Research Institute that will greatly accelerate studies of the most lethal forms of human malaria.

Plasmodium falciparum, one of two human-specific malaria parasites, is a global health crisis, causing more than 216 million new infections annually and resulting in an estimated 655,000 deaths, according to the World Health Organization.

Sporozoites, the infectious form of the parasite, are spread to people through the bites of infected mosquitos and multiply in the human liver during the initial stages of infection. There, they undergo liver stage development, culminating in the formation and release of tens of thousands of merozoites, the parasitic phase of development that infects red blood cells.

Until now, there have been few data on human malaria liver stage biology due to the lack of a viable small animal model and because liver stage P. falciparum does not grow well in a dish. Consequently, most research and therapeutics to date have targeted the human blood stage of P. falciparum’s development because it replicates well in culture.

The liver-to-blood stage of P. falciparum is the focus of this research because the parasite is virtually harmless, causing no disease symptoms, prior to its transition to the blood stage.

In this study, researchers at Seattle Biomedical Research Institute, Yecuris Corporation, Oregon Health & Science University and The Rockefeller University have demonstrated that a complete liver-to-blood stage infection of P. falciparum is possible using a unique immunocompromised mouse model engrafted with human liver-chimeric cells.

With this new data, physicians and scientists can better fight the disease.

It’s not the first time humanized mice have come to the rescue. In 2007, we announced the use of these unique mice to create human liver cells so that new drugs can be tested in the fight against liver disease. More info in this story.