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Kyoto University creates the world’s first immunodeficient rats!

Program-Specific Associate Professor Tomoji Mashimo and his research team at Kyoto University have achieved a world first in creating severe immunodeficient rats that have no immune cells. While conventional methods have been used to create severe immunodeficient mice, no technology had yet been established to create severe immunodeficient rats. This finding was published in the online edition of the American science journal Cell Reports.

The team succeeded in creating rats with no immune cells by using a specific artificial enzyme to remove specific genes from the rats’ DNA. After transplanting human iPS cells (induced pluripotent stem cells), human cancer cells, and human liver cells into those rats, the team confirmed that these cells proliferated with no rejection. According to the team, compared to normal rats, severe immunodeficient rats weighed 30% less, and had a lower cell proliferation rate, which are NOT characteristics observed in severe immunodeficient mice and similar to that found with human immunodeficiency.

Since a rat is 10 times larger than a mouse, it is possible to sample blood, bile, and cells repeatedly. Professor Mashimo said, “Being larger than mice, rats are easy to handle and have an anatomical structure similar to that of humans, which makes them suitable to be experimental animals. I hope that our technology will be widely used in such research fields as cancer research, stem cell research, transplantation research, and drug discovery research.”

 
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The slightly smaller ones are severe immunodeficient rats (ones on the right).
 
Contact : Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University
Phone or E-mail +81-75-753-9318