Mosquitoes Ramp Up Immune Defences After Sucking Blood, Finds Study

With malaria and other vector-borne diseases, we're faced with problems of not having effective vaccines and insecticide-resistant vectors. But it seems that mosquitoes do a great job of controlling infection in their own bodies. A new study has found that mosquitoes ramp up their immune system after drinking blood to help fight off the parasites that blood might contain.

Michael Povelones, an assistant professor in the University of Pennsylvania's School of Veterinary Medicine, who co-authored the study said that, "This appears to be a new mechanism by which the mosquito is anticipating a parasite infection. If we can use that information to our advantage, we might be able to find new avenues of preventing mosquitoes from transmitting disease."

Scientists already knew that a group of molecules called leucine-rich repeat immune proteins were important players in mosquitoes' immune defence.

Povelones and colleagues earlier reported that two of these LRIMs, LRIM1 and APL1C, are part of a signalling pathway akin to the human complement system, which coordinates immune response through a cascade of signalling interactions.

In mosquitoes, LRIM1 and APL1C helped target malarial parasites for destruction. In the latest study, the scientists wanted to gain a deeper understanding of what the other identified LRIM proteins - there are at least two dozen - did for mosquito immunity.

From their tests, one protein, LRIM9, stood out. When it was blocked, parasite levels in the mosquitoes increased three-fold.

Researchers found that adult females had the highest expression levels of LRIM9, with more than 20 times the amount of LRIM9 as adult males. Adult females are the only mosquitoes that drink blood.

They noted that LRIM9 may help the mosquito immune system recognise pathogens and may also recruit or interact with other immune system components. The study was published in the Journal of Innate Immunity.

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Source-Medindia