Researchers have successfully engineered hookworms to produce and secrete an antibody inside a living host, a milestone that could one day allow parasites to replace pills and injections for people with chronic diseases.
The results, released June 3 in Nature Communications, have been obtained by a group under the supervision of Makedonka Mitreva, a molecular geneticist at the Washington University School of Medicine in St Louis.
The researchers employed a procedure called electroporation, which involves sending electric shocks to the membranes of the cells to open tiny pores for delivering the CRISPR/Cas9 tools of gene editing to the eggs of Ancylostoma ceylanicum worms.
The genetically programmed cargo was to direct the worms to produce antibodies capable of neutralising tetrodotoxin, a deadly substance produced by certain pufferfishes with no known antivenom.Â
The Defence Advanced Research Projects Agency (DARPA), which financed the study, wants to find ways to deal with a potential biochemical threat posed by the toxin.
Antibody fragments could be detected in hamsters’ blood when the animals were infected with the genetically engineered worms, thus accounting for about 20% of the toxin neutralised in laboratory experiments.
Although the findings were welcomed by experts outside the experiment, there was still no doubt about their limitations.Â
For example, Cornelis Hokke, a parasitology expert from Leiden University Medical Center in the Netherlands, observed that 20% inhibition might not be adequate protection for any host against tetrodotoxin exposure, which is very powerful and must be almost totally inhibited for survival.
UCLA parasitologist Elissa Hallem said that the most important thing in the current research is the DNA delivery achievement, which might pave the way toward producing more parasites.
