A drug could be injected into human cells

From the syringe to the cells: the bioluminescent bacterium P. asymbiotica using an artificial intelligence system

While Zhang and his collaborators searched for ways of transporting proteins into human cells, microbiologists were learning more about an unusual group of bacteria that use molecular spikes to pierce a hole in the membranes of host cells. The bacteria then transport proteins through the perforation and into the cell, exploiting the host’s physiology in their favour.

According to Jiang, it is astonishing that the Chinese Academy of Medical Sciences Institute of Pathogen Biology is in Beijing. It is a big breakthrough.

The system was unable to transport the mRNA guide needed for CRISPR–Cas9 genome editing, but the team is developing ways to do this, says Kreitz. The system was able to deliver the protein to the cells in a large enough size that it speaks to the technique’s flexibility.

Last year, Jiang and his colleagues reported that they could manipulate this syringe-like system in the bioluminescent bacterium Photorhabdus asymbiotica, loading proteins of their choosing from mammals, plants and fungi into the syringe2. Normally, the bacterium lives inside nematodes and uses its syringe to transport a toxin into the cells of insects infected by the nematode. The toxin kills the insect, and the nematode eats the remains. Joseph is a co-author of the book and says the bacterium can be used to kill the insect.

The P. asymbiotica would be able to recognize human cells if the engineers in the lab were able to engineer it. They focused on a place known as the tail fibre, which helps bind a molecule to a cell’s nucleus. The team used artificial intelligence to modify the tail fibre to recognize mouse and human cells. “Once we had the image, it was very easy to modify it for our uses,” says Kreitz. “That was the moment when it all came together.”

Asaf Levy, a Computational Microbiologist at the Hebrew University, says that the story is similar to the way that researchers such as Zhang developed the CRISPR-Cas9 system for use as a genome-editing technique. The roles of the bacterial needles in the ecology of organisms are still being understood, just like they were with the early days ofCRISPR–9 research.

Levy says they could have a dramatic effect on medicine. He says that the evolution of this thing is amazing. The fact that you can engineer both the specificity and the payload is very cool.

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