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(left) and Jeffrey Wagner
Credit: Bryce Vickmark
The gene-editing technique CRISPR can disrupt a single gene from the malaria parasite Plasmodium falciparum in a matter of weeks, a new study suggests.
Although CRISPR’s success rate ranged from 50% to 100%, the researchers believe the technique shows promise and could greatly speed up gene analysis.
At present, it can take up to a year to determine the function of a single gene in P falciparum, which can hinder efforts to develop drugs and vaccines.
“Even though we’ve sequenced the entire genome of Plasmodium falciparum, half of it still remains functionally uncharacterized,” said Jacquin Niles, MD, PhD, of the Massachusetts Institute of Technology in Cambridge.
“That’s about 2500 genes that, if only we knew what they did, we could think about novel therapeutics, whether it’s drugs or vaccines.”
Dr Niles and his colleagues described their use of CRISPR in P falciparum in Nature Methods.
The team noted that, in P falciparum, gene editing can take up to a year because it relies on homologous recombination, a type of genetic swapping that cells use to repair broken DNA strands and that occurs very rarely in the genome of the malaria parasite.
“You have to rely on this really inefficient process that occurs only if you have spontaneous DNA strand breaks that happen to fall within your region of interest,” Dr Niles said.
More recently, researchers have successfully used zinc finger nucleases to cut out specific genes, but this approach is costly because it requires a new nuclease to be designed for each gene target.
CRISPR exploits a set of bacterial proteins that protect microbes from viral infection. The system includes a DNA-cutting enzyme, Cas9, bound to a short RNA guide strand that is programmed to bind to a specific genome sequence, telling Cas9 where to make its cut. This approach allows scientists to target and delete any gene by simply changing the RNA guide strand sequence.
As soon as researchers proved this system could work in cells other than bacteria, Dr Niles started to think about using it to manipulate P falciparum.
To test this approach, he and his colleagues tried using CRISPR to disrupt 2 genes, kahrp and eba-175, that had previously been knocked out in malaria using traditional approaches.
The kahrp gene produces a protein that causes red blood cells to develop a knobby appearance when infected with malaria. Dr Niles’s team was able to disrupt this gene in 100% of parasites treated with the CRISPR system. The red blood cells infected by parasites remained smooth.
The other gene, eba-175, codes for a protein that binds to red blood cell receptors and helps the malaria parasite enter cells. The researchers were only able to disrupt this gene in 50% to 80% of parasites manipulated with CRISPR.
“We consider this to be a win,” Dr Niles said. “Compared to the efficiency with which P falciparum genetics have been done in the past, even 50% is pretty substantial.”
Now that CRISPR technology has been validated in P falciparum, Dr Niles expects many scientists will adopt it for genetic studies of the parasite. Such efforts could reveal more about how the parasite invades red blood cells and replicates inside cells, which could generate new drug and vaccine targets.
“I think the impact could be quite huge,” he said. “It lowers the barrier to really being more imaginative in terms of how we do experiments and the kinds of questions that we can ask.” 
(left) and Jeffrey Wagner
Credit: Bryce Vickmark
The gene-editing technique CRISPR can disrupt a single gene from the malaria parasite Plasmodium falciparum in a matter of weeks, a new study suggests.
Although CRISPR’s success rate ranged from 50% to 100%, the researchers believe the technique shows promise and could greatly speed up gene analysis.
At present, it can take up to a year to determine the function of a single gene in P falciparum, which can hinder efforts to develop drugs and vaccines.
“Even though we’ve sequenced the entire genome of Plasmodium falciparum, half of it still remains functionally uncharacterized,” said Jacquin Niles, MD, PhD, of the Massachusetts Institute of Technology in Cambridge.
“That’s about 2500 genes that, if only we knew what they did, we could think about novel therapeutics, whether it’s drugs or vaccines.”
Dr Niles and his colleagues described their use of CRISPR in P falciparum in Nature Methods.
The team noted that, in P falciparum, gene editing can take up to a year because it relies on homologous recombination, a type of genetic swapping that cells use to repair broken DNA strands and that occurs very rarely in the genome of the malaria parasite.
“You have to rely on this really inefficient process that occurs only if you have spontaneous DNA strand breaks that happen to fall within your region of interest,” Dr Niles said.
More recently, researchers have successfully used zinc finger nucleases to cut out specific genes, but this approach is costly because it requires a new nuclease to be designed for each gene target.
CRISPR exploits a set of bacterial proteins that protect microbes from viral infection. The system includes a DNA-cutting enzyme, Cas9, bound to a short RNA guide strand that is programmed to bind to a specific genome sequence, telling Cas9 where to make its cut. This approach allows scientists to target and delete any gene by simply changing the RNA guide strand sequence.
As soon as researchers proved this system could work in cells other than bacteria, Dr Niles started to think about using it to manipulate P falciparum.
To test this approach, he and his colleagues tried using CRISPR to disrupt 2 genes, kahrp and eba-175, that had previously been knocked out in malaria using traditional approaches.
The kahrp gene produces a protein that causes red blood cells to develop a knobby appearance when infected with malaria. Dr Niles’s team was able to disrupt this gene in 100% of parasites treated with the CRISPR system. The red blood cells infected by parasites remained smooth.
The other gene, eba-175, codes for a protein that binds to red blood cell receptors and helps the malaria parasite enter cells. The researchers were only able to disrupt this gene in 50% to 80% of parasites manipulated with CRISPR.
“We consider this to be a win,” Dr Niles said. “Compared to the efficiency with which P falciparum genetics have been done in the past, even 50% is pretty substantial.”
Now that CRISPR technology has been validated in P falciparum, Dr Niles expects many scientists will adopt it for genetic studies of the parasite. Such efforts could reveal more about how the parasite invades red blood cells and replicates inside cells, which could generate new drug and vaccine targets.
“I think the impact could be quite huge,” he said. “It lowers the barrier to really being more imaginative in terms of how we do experiments and the kinds of questions that we can ask.”
(left) and Jeffrey Wagner
Credit: Bryce Vickmark
The gene-editing technique CRISPR can disrupt a single gene from the malaria parasite Plasmodium falciparum in a matter of weeks, a new study suggests.
Although CRISPR’s success rate ranged from 50% to 100%, the researchers believe the technique shows promise and could greatly speed up gene analysis.
At present, it can take up to a year to determine the function of a single gene in P falciparum, which can hinder efforts to develop drugs and vaccines.
“Even though we’ve sequenced the entire genome of Plasmodium falciparum, half of it still remains functionally uncharacterized,” said Jacquin Niles, MD, PhD, of the Massachusetts Institute of Technology in Cambridge.
“That’s about 2500 genes that, if only we knew what they did, we could think about novel therapeutics, whether it’s drugs or vaccines.”
Dr Niles and his colleagues described their use of CRISPR in P falciparum in Nature Methods.
The team noted that, in P falciparum, gene editing can take up to a year because it relies on homologous recombination, a type of genetic swapping that cells use to repair broken DNA strands and that occurs very rarely in the genome of the malaria parasite.
“You have to rely on this really inefficient process that occurs only if you have spontaneous DNA strand breaks that happen to fall within your region of interest,” Dr Niles said.
More recently, researchers have successfully used zinc finger nucleases to cut out specific genes, but this approach is costly because it requires a new nuclease to be designed for each gene target.
CRISPR exploits a set of bacterial proteins that protect microbes from viral infection. The system includes a DNA-cutting enzyme, Cas9, bound to a short RNA guide strand that is programmed to bind to a specific genome sequence, telling Cas9 where to make its cut. This approach allows scientists to target and delete any gene by simply changing the RNA guide strand sequence.
As soon as researchers proved this system could work in cells other than bacteria, Dr Niles started to think about using it to manipulate P falciparum.
To test this approach, he and his colleagues tried using CRISPR to disrupt 2 genes, kahrp and eba-175, that had previously been knocked out in malaria using traditional approaches.
The kahrp gene produces a protein that causes red blood cells to develop a knobby appearance when infected with malaria. Dr Niles’s team was able to disrupt this gene in 100% of parasites treated with the CRISPR system. The red blood cells infected by parasites remained smooth.
The other gene, eba-175, codes for a protein that binds to red blood cell receptors and helps the malaria parasite enter cells. The researchers were only able to disrupt this gene in 50% to 80% of parasites manipulated with CRISPR.
“We consider this to be a win,” Dr Niles said. “Compared to the efficiency with which P falciparum genetics have been done in the past, even 50% is pretty substantial.”
Now that CRISPR technology has been validated in P falciparum, Dr Niles expects many scientists will adopt it for genetic studies of the parasite. Such efforts could reveal more about how the parasite invades red blood cells and replicates inside cells, which could generate new drug and vaccine targets.
“I think the impact could be quite huge,” he said. “It lowers the barrier to really being more imaginative in terms of how we do experiments and the kinds of questions that we can ask.”