A malaria Plasmodium in the form that enters humans from the saliva of female mosquitoes.
Once it’s in the blood stream, the malaria parasite can invade a human red blood cell (RBC) in less than one minute, making it hard for researchers to study disease development at the cellular level. A team of scientists from the United Kingdom are using laser optical tweezers, which offer precise control over cell and pathogen manipulation, to study how the malaria parasite Plasmodium falciparum infects RBCs (Biophys. J., doi: 10.1016/j.bpj.2014.07.010). The researchers hope that a better understanding of P. falciparum RBC invasion will lead to more effective treatments and possibly vaccines for this sometimes deadly disease.
To survive, the malaria parasite needs to get inside an RBC; therefore, the invasion period of its life cycle is a good target for designing malaria drugs and vaccines. Senior study authors Julian Rayner of the Wellcome Trust Sanger Institute and Pietro Cicuta of the University of Cambridge developed a method for using optical tweezers to trap and deliver one parasite to a single RBC, proving the technique can be used to observe individual cell invasion (click here for a video). In another invasion procedure, they used the tweezers to measure how strongly P. falciparum adheres to the RBC prior to invasion, which could identify attachment points to block with drugs or antibodies. The researchers also used the tweezers to study the mechanisms of action of three existing invasion-inhibiting malaria medications.
Next, the team plans to use optical tweezers to understand what genes and proteins are involved with P. falciparum invasion in hopes of designing anti-invasion treatments or vaccines that can disable several of these targets at the same time.
Although most malaria cases and deaths occur in Africa, the World Health Organization (WHO) reports that over 97 countries and territories—including those in Asia, Latin America, the Middle East and Europe—have ongoing malaria transmission. WHO estimates that in 2012, malaria infected 207 million people and killed 670,000.