Blood tied. The malaria parasite P. falciparum, which is carried by the Anopheles mosquito (pictured in their larval stage), can't infect red blood cells without a particular protein.
Credit: Wellcome Trust Sanger Institute
Posted on 11/13/2011 9:51:27 PM PST by neverdem
The most dangerous malaria parasite, Plasmodium falciparum, is an unusually versatile bug. The single-celled safecracker carries a wide collection of protein "keys" that it can use to jimmy receptor "locks" on the surface of red blood cells, tricking the cells into letting it in. Block one of these entry points with a drug, and the parasite just uses a different key.
But now, researchers believe they may have found a master key that the parasite uses—a surface protein without which it's unable to invade blood cells. The researchers hope the finding will help them design a new malaria vaccine.
Such a vaccine has been "a difficult nut to crack," Gavin Wright of the Wellcome Trust Sanger Institute in Cambridge, U.K., said at a press briefing about the study in London on Monday. Not only does P. falciparum have numerous keys—scientifically known as ligands—at its disposal, figuring out which ligand key interacts with which of the hundreds of receptors on a cell's surface is a challenge. And it's difficult to study in the lab because ligands bound to receptors quickly rip apart when scientists put them through the chemical washes and treatments needed to identify them.
So, along with malaria researcher Julian Rayner, also of the Sanger Institute, Wright's group developed a chemical treatment that stabilizes the receptors and ligands so that they will remain stuck together longer for researchers to study. When they used this method to look at one of P. falciparum's known "keys," a surface protein called PfRh5, the researchers saw that it interacted with a receptor protein called basigin, sticking off the surface of red blood cells. Using mutated stem cells, the researchers made red blood cells that lacked basigin and discovered that P. falciparum was completely unable to invade. Covering basigin with antibodies also blocked the parasite from getting in.
The researchers tested 15 different strains of P. falciparum, taken straight from malaria patients, and found that none of them were able to invade red blood cells if basigin was unavailable. This makes the interaction between basigin and PfRh5 a promising target for a vaccine, the team reports online today in Nature. Injecting the protein PfRh5 into patients could kick-start the immune system into making antibodies against PfRh5 and prepare for infection by an actual pathogen. The vaccine is still a long way off, the researchers said at the press conference, but they have already found that PfRh5 is easy to produce in large quantities, which is a major hurdle for some vaccines.
"It's a very nice paper," says molecular parasitologist Alan Cowman of the Walter and Eliza Hall Institute of Medical Research in Parkville, Australia. The interaction between basigin and PfRh5 is clearly far more important than other interactions discovered so far, he notes. But as far as a vaccine goes, Cowman says Plasmodium could become resistant against it by finding new entry routes. To prevent that from happening, "my feeling is that [injecting PfRh5] needs to be in combination with other proteins. I'd be wary of using one by itself."
Rayner agrees that a vaccine based on PfRh5 could be used together with others, such as the modestly successful RTS,S vaccine currently being tested by GlaxoSmithKline, which targets the pathogen at a different stage in its life cycle.
micro/immunology ping
Cure malaria? Can’t have that. Isn’t the mosquito endangered? What would PETA say.
They pretty much had it licked until Rachel Carson caught on....
SC - This is not GGG or Catastrophism, but it is science, so I thought you might want to see it.
SunkenCiv is on my health & science list, so you only gave a early heads-up. I believe blam is on SunkenCiv’s list for science stories, but I could be wrong.
The miracle of specificity of proteins still can’t make the atheistic pretenders to science even acknowledge God, can it. We’ve got computer programs written into our very flesh, and no, it’s all random according to them. You can write poems and e-mail addresses onto bacterial DNA, and it’s all random chance . . . yeah right.
DDT!
Sounds better than those diarrhea cussing pills we were supposed to take 40 years ago.
Science does not exist to demonstrate the existence or non-existence of God, nor is that the motivation of scientists. Proteins do not become specific because of a "miracle"; they become that way because of evolution, in which the proteins mutate randomly, and all the mutations that don't work fail to survive. God may have set up the rules by which the physical world works, but continued instructions are not needed.
I am very willing to let them test the vaccine on me.
As we remove many/most of natures methods of human population control, who will feed the growing third world populations who, until now have mostly been unable to feed themselves?
Continuing to bring them to western countries (under the pretense of refugees) and have them attack the people and system that supports them will doom us all. When you run out of food, there are wars and refugees.
We now have the children of refugees volunteering as suicide bombers while living on welfare benefits. (What happened to the American Dream?)
Diversity is our strength. Bullshit!
We have a preponderance of scientists that seem dedicated towards demonstrating the latter.
Science does not exist to demonstrate the existence or non-existence of God, nor is that the motivation of scientists
No scientific observation for that.
Proteins do not become specific because of a "miracle"; they become that way because of evolution, in which the proteins mutate randomly, and all the mutations that don't work fail to survive
Wait until the mullahs start pushing buttons.
God may have set up the rules by which the physical world works, but continued instructions are not needed
Guess if I worked in Indonesia I’d be looking forward to it too, but I left Southeast Asia 43 years ago and doubt I’ll ever return. I experienced malaria way back when and occasionally had a reoccurrence for about 20 years afterwards. It wasn’t fun.
Actually, not. I've never yet met a scientist dedicated to trying to prove that God does not exist. Most of us are too busy doing research; setting out to prove God doesn't exist would be futile and pointless. The small minority of scientists who try to publicly use science to disprove God really aren't typical or representative of scientists. And they make the rest of us look bad.
No scientific observation for that.
The processes of evolution have been quite well characterized, and details continue to be uncovered. Mutations happen all the time.
You're just corroded with jealousy cause you didn't think of it first...
Cheers!
Thanks!
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