Image: A blood sucking tick
Original Published Date: 
Tuesday, March 29, 2016

Researchers at the ARC Centre of Excellence in Advanced Molecular Imaging at Monash University, together with the University of Oxford, have discovered how proteins present in tick saliva prevent the immune system from running amok. The research team revealed a connection between an important therapeutic, ‘Eculizumab’, and proteins in tick saliva. Eculizumab, sold under the name Soliris, is currently the only therapeutic available for treating life threatening blood disorders—Paroxysmal nocturnal hemoglobinuria (PNH) and atypical haemolytic-uremic syndrome (aHUS). In these diseases, the immune system attacks and destroys blood cells. Soliris works by shutting down part of our immune system. When ticks bite an unsuspecting victim, they inject substances that inhibit the same part of the immune system that Solaris targets. These substances allow the insect to stay attached and feed on people for up to ten days without the immune system recognising and destroying them. The team set out to understand how these insects can shut down an immune reaction, using a combination of X-ray crystallography and powerful microscopes to look into the molecular structures of both the tick proteins and Soliris in complex with the immune proteins they bind. Professor Susan Lea, Oxford University and visiting academic at Monash University said that the tick proteins are much smaller and easier to make than the antibodies in Soliris and may result in much cheaper therapies for a range of different immune disorders.

Media issued by the ARC Centre of Excellence in Advanced Molecular Imaging.

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Image courtesy: sergio venturi of