Researchers find that immune system messengers slow malaria fight

Scientists from QIMR Berghofer Medical Research Institute have found that a particular family of biological messengers in the immune system hinders the fight against malaria infection.

The World Health Organisation estimates that malaria killed 438,000 people worldwide in 2015. It’s estimated that more than 300,000 of those deaths were in children under the age of five.

The head of QIMR Berghofer’s Malaria Immunology Laboratory, Dr Ashraful Haque, said the human immune system was slow to develop the number of antibodies it needed to successfully fight malaria infection.

“This means that people in malaria-endemic areas typically aren’t able to fight off the disease without drugs until late childhood or adolescence,” Dr Haque said.

“We wanted to find out whether something in particular was slowing down the production of antibodies.”

Cytokines are biological messengers that are secreted by the immune system. They trigger a series of actions, which leads to the production of antibodies.

“In this study we looked at a particular family of cytokines, known as type I interferons,” Dr Haque said.

“We essentially blocked this family of biological messengers by removing a molecule from the surface of immune cells that receives and conveys its message. When we did this, we found that antibodies were produced more quickly.

“Our findings mean that this family of immune messengers has an immunosuppressive effect. In this study we have shown for the first time that type 1 interferons hinder the process that leads to the production of antibodies.

“If we can block these messengers in humans, we think this may improve the immune system’s response to malaria infection.

“We know that type 1 interferons are crucial in fighting off many viruses. It’s not clear at this stage why they hinder the body’s response to malaria.”

These findings back up a recent study by QIMR Berghofer’s Immunology and Infection Laboratory, which found that type I interferons suppressed immune responses in human volunteers infected with malaria parasites.

The findings of Dr Haque’s study have been published in the journal Plos Pathogens. The study was funded by the National Health and Medical Research Council.