K-State researchers study insects' immune system

How insects avoid getting diseases they can carry and spread to humans is the focus of research at Kansas State University.

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

The researchers have made progress in understanding which molecules are present in the blood and their functions. The group also has identified proteins involved in the immune response that cause melanin - a coating of black pigment - to be synthesized and deposited on the surface of the pathogen.

The goal of their research is to understand how insects recognize infection caused by microorganisms such as viruses, bacteria and fungi, and the pathway of reactions that follow in the immune system.

Studying the immune system of insects is important because it can lead to useful knowledge for the improvement of biological pesticides, Kanost said. Such a method of pest control only kills specific insects and is safe for humans.

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

For a mosquito to bite one human, acquire a disease and then transfer it to the next person it bites poses an interesting concept for researchers. For the disease to spread, it has to survive for a certain period of time in the mosquito. The question is, how does the pathogen survive?

For a disease like malaria, the parasite has to live in an insect's blood for part of its life cycle, all the while exposed to the mosquito's immune system. A successful parasite has to avoid the immune system or be able to defend against it. Understanding how a pathogen can survive might result in ways to disrupt the transmission of diseases, 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 what the immune responses are but how they are regulated is a big question we need to study," Kanost said. "To me, one of the aspects that's interesting is even if we understand the immune system of one species of insect very well, there are millions of species of insects and they're all different from each other. Even though they will have some things in common, there's a lot to do for many lifetimes for people doing research on biochemistry in insects."

Researchers involved with the study include Maureen Gorman, research assistant professor in biochemistry, and Chansak Suwanchaichinda and Shufei Zhuang, both postdoctoral biochemistry research 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 and pre-medicine, and Emily Ragan, graduate student in biochemistry, all of Manhattan.

Source : Kansas State University