Human insulin suppresses mosquito immune system: Increasing cases of type 2 diabetes could abet malaria's spread

June 19, 2012

Human insulin suppresses the mosquito immune system, according to a paper in the June Infection and Immunity. And while mosquitoes and malaria might seem to go together like baseball and hotdogs, mosquitoes' immunological resistance to the malaria parasite actually slows its spread among H. sapiens.

"A fair portion actually fight off the infection," says first author Nazzy Pakpour of the University of California, Davis.

But now the rate of is climbing in Africa as in most of the rest of the world, to the point where by 2030, one in five adults there are predicted to be so-afflicted. More diabetes means more hyperinsulinemia—more human insulin to inhibit mosquitoes' immune response to Plasmodium falciparum, thus aiding and abetting transmission of this dread disease.

As horrific as the medical consequences of all this might be, the science is intriguing. "It's crazy to think something in our blood could change how mosquitoes respond to parasites," says Pakpour.

In earlier work, Pakpour and collaborators showed that ingested human insulin activates the insulin/IGF-1 signaling pathway in Anopheles stephensi , making them more vulnerable to invasion by P. falciparum. The new study showed that insulin signaling reduced expression of certain mosquito immunity genes that are under the same regulatory control, and that human insulin suppressed mosquito immunity by activating the so-called PI3K signaling pathway, and that artificially inhibiting that pathway could reverse the immunosuppressive effects of human insulin.

Explore further: Wolbachia bacteria reduce parasite levels and kill the mosquito that spreads malaria

More information: N. Pakpour, V. Corby-Harris, G.P. Green, H.M. Smithers, K.W. Cheung, M.A.Riehle, and S. Luckhart, 2012. Ingested human insulin inhibits the mosquito NF-KAPPAB-dependent immune response to Plasmodium falciparum. Infect. Immun. 80:2141-2149. Download the journal article at http://bit.ly/asm061912a

Related Stories

Scientists engineer mosquito immune system to fight malaria

December 22, 2011

Researchers at the Johns Hopkins Malaria Research Institute have demonstrated that the Anopheles mosquito's innate immune system could be genetically engineered to block the transmission of malaria-causing parasites to humans. ...

Recommended for you

Nature study suggests new therapy for Gaucher disease

February 22, 2017

Scientists propose in Nature blocking a molecule that drives inflammation and organ damage in Gaucher and maybe other lysosomal storage diseases as a possible treatment with fewer risks and lower costs than current therapies.

T cells support long-lived antibody-producing cells

February 21, 2017

If you've ever wondered how a vaccine given decades ago can still protect against infection, you have your plasma cells to thank. Plasma cells are long-lived B cells that reside in the bone marrow and churn out antibodies ...

Understanding how HIV evades the immune system

February 21, 2017

Monash University (Australia) and Cardiff University (UK) researchers have come a step further in understanding how the human immunodeficiency virus (HIV) evades the immune system.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.