K-State Researchers Study Insects' Immune System

Mike Kanost, university distinguished professor of biochemistry andhead of the department of biochemistry, and researchers in his lab arestudying how insects protect themselves against infection. They thinkthe answer lies in insects' blood, specifically proteins.

The researchers have made progress in understanding whichmolecules are present in the blood and their functions. The group alsohas identified proteins involved in the immune response that causemelanin - a coating of black pigment - to be synthesized and depositedon the surface of the pathogen.

The goal of their research is to understand how insectsrecognize infection caused by microorganisms such as viruses, bacteriaand fungi, and the pathway of reactions that follow in the immunesystem.

Studying the immune system of insects is important because itcan lead to useful knowledge for the improvement of biologicalpesticides, Kanost said. Such a method of pest control only killsspecific insects and is safe for humans.

A recent development for Kanost's group is the transition fromstudying caterpillars to studying mosquitoes, which have a more directimpact on humans. Understanding how proteins in mosquitoes' bloodfunction in immune responses may help identify ways to disrupt diseasetransmission by blood-feeding insects. Knowledge gained from examiningcaterpillars is being used to understand the mosquito's immune system,Kanost said.

For a mosquito to bite one human, acquire a disease and thentransfer it to the next person it bites poses an interesting conceptfor researchers. For the disease to spread, it has to survive for acertain period of time in the mosquito. The question is, how does thepathogen survive?

For a disease like malaria, the parasite has to live in aninsect's blood for part of its life cycle, all the while exposed to themosquito's immune system. A successful parasite has to avoid the immunesystem or be able to defend against it. Understanding how a pathogencan survive might result in ways to disrupt the transmission ofdiseases, Kanost said.

"Insects are the most abundant kind of animal," he said."They're very successful animals. If you want to understand biology,understanding insects is important.

"We're at a point now where we understand at least some of whatthe immune responses are but how they are regulated is a big questionwe need to study," Kanost said. "To me, one of the aspects that'sinteresting is even if we understand the immune system of one speciesof insect very well, there are millions of species of insects andthey're all different from each other. Even though they will have somethings in common, there's a lot to do for many lifetimes for peopledoing research on biochemistry in insects."

Researchers involved with the study include Maureen Gorman,research assistant professor in biochemistry, and ChansakSuwanchaichinda and Shufei Zhuang, both postdoctoral biochemistryresearch associates.

K-State students taking part in the research are Ana Fraire,junior in biochemistry and pre-medicine, Liberal; and Craig Doan,sophomore in biochemistry, Rose Ochieng, senior in biochemistry andpre-medicine, and Emily Ragan, graduate student in biochemistry, all ofManhattan.

This research is funded by grants from the National Institutes of Health.