Who would have imagined that moths are as good as mice for many drug tests?
Biologists have discovered that certain key cells in mammals and insects react in the same way when attacked by infections and produce similar chemical reactions to fight them off.The findings could mean up to 80 percent of the mice used for testing new pharmaceutical compounds may no longer be needed, offering drug firms sizeable time and cost savings.
“It is now routine practice to use insect larvae to perform initial testing of new drugs and then to use mice for confirmation tests,” said Kevin Kavanagh, a biologist from the National University of Ireland, who presented his research at a Society for General Microbiology meeting in Edinburgh.
“This method of testing is quicker, as tests with insects yield results in 48 hours whereas tests with mice usually take 4 to 6 weeks. And it is much cheaper too.”
Kavanagh and his colleagues found that neutrophils, white blood cells that form part of the mammalian immune system, and haematocytes, cells that carry out similar work in insects, react in the same way to infecting microbes.
Both the insect and mammalian cells produce chemicals with a similar structure which move to the surface of the cells to kill the invading microbe, they found. The immune cells then enclose the microbe and release enzymes to break it down.“We used insects instead of mammals for measuring how pathogenic a bacterium or fungus is, and found a very good correlation between the results in mammals and insects,” Kavanagh said in a telephone interview.
“The reason for this … is that the innate immune system of mammals is almost 90 percent similar to that of insects.”