Science / Medicine : Immune Systems in Insects

The first evidence that insects can have an immune system similar to that found in animals was presented last week at a meeting of the Federation of American Societies for Experimental Biology (FASEB) by researchers from the University of Cincinnati. The results contradict the longstanding belief that insects have much more primitive defenses against disease.

Immunologist Richard D. Karp and his colleagues found that cockroaches can produce proteins that are similar in size and function to animal antibodies--proteins that bind to foreign chemicals and organisms in the blood and mark them for destruction. They found that roaches react to a small injection of honeybee venom by producing antibody-like compounds in their hemolymph (blood). When the immunized roaches are then injected with a normally fatal dose of venom, they survive.

Furthermore, when the antibody-like proteins were isolated from immunized roaches and injected into other roaches, the recipients were protected against a lethal dose of the venom, just as is the case with animal antibodies.

“The reason I study insects is to look for the genetic origins of immunity,” Karp said. “That will give us a better insight into the immunity of higher animals.” Karp speculated that the study might also lead to development of new pesticides that could overcome insects’ resistance to existing ones.