Move over, Charles Darwin. According to National University of Ireland pioneering biologist Kevin Kavanagh, because an insect’s immune system - specifically its haematocytes - closely resembles one part of the mammalian immune system - or its neutrophils - using moths, caterpillars or Drosophila (fruit flies) instead of mice and rats just seemed like the next step - and a more humane one - in the evolution of drug research and testing.
"It was just a hunch when the project began in the late 1990s," Dr. Kavanagh said by phone from his university office, acknowledging that "speed, reduced cost, and greater ethical acceptance" are byproducts of the model. Because insects are much smaller with a shorter lifespan, results can be measured in a day or two, and at a cost of under 32 cents, as opposed to six weeks and $80-$130 in murine (rodent) specimens, he explained, noting the prevalence of the practice in the British Isles and Europe.
In the U.S., M.D. Anderson Cancer Center infectious disease specialist Dr. Dimitrios Kontoyiannis, whose pathogenic research with Drosophila under these conditions also spans a decade, calls the model "an emerging area in immunopathogenics, and for sure not yet mainstream." Murine models, he says, are "laborious" and have "ethical implications," though both Kontoyiannis and Kavanagh maintain that insects are typically used for the initial screen with testing ultimately validated in mice. Still, the practice, as it is, can preclude the use of hundreds or even thousands of mammals in a single drug test, a giant stride for mice and men toward more humane laboratory research.