Radio review: Science in Action - CRISPR immunity

As a law graduate with a special interest in medical law and bioethics, I admit to having limited scientific background knowledge. Understanding a new scientific procedure or medical treatment can be challenging: often I will spend considerable time researching scientific terms and how a procedure works before fully grasping what a scientific article or research paper is talking about.

When I discovered that I would be reviewing a programme on how the human immune system could dampen the effects of the Cas9 protein, (part of the CRISPR/Cas9 approach to genome editing) if it were ever used in human therapies, I was mentally prepared for intensive research on understanding even the basic terms used in the programme.

However, much to my surprise, the BBC World Service's series Science in Action never made me feel that my lack of scientific knowledge would affect my understanding of the conversation.The section of the programme discussing human immune system response to the DNA-cutting protein Cas9 was a conversation between the host Roland Pease, and Professor Matthew Porteus, a professor of paediatrics in Stanford University.

The main point of discussion was based on the recent research from Stanford, which explores whether our immune system could get in the way of efforts to use genome editing to treat genetic conditions. When Cas9 was mentioned, I was worried that this was the moment where things would stop making sense. However, Professor Porteus provided a reassuring explanation, clarifying that Cas9 is a revolutionary tool for genome editing that allows us to make changes in the DNA of cells, with the potential to cure diseases. 

The conversation became even more interesting when the issues that could hinder the use of Cas9 were discussed. Cas9 is a protein derived from bacteria, and our immune systems may naturally generate an immune response to eliminate it, creating the possibility that our bodies have already built up immunity to the protein.

Professor Porteus did well to give the necessary information, explaining how the immune system will respond and attack a foreign protein introduced into the body. He explained that blood from healthy adults was screened and found to contain antibodies which would recognise two forms of the protein, indicating a pre-existing immunity to Cas9 (see BioNews 933).

I was very intrigued when Professor Porteus stated that the results indicated that 70 percent of the adults had pre-existing antibodies for both forms of Cas9. Although my initial question was whether these findings meant that Cas9 would not be useful in humans, the host decided not to probe this until later on. Instead, Pease opted to ask about what the possible effects of injecting the protein in him would be. While Professor Porteus could not give an accurate answer, as the findings at that point were not sufficient, he did well to provide the audience with all the possibilities, and the different reactions the body could have.

I was delighted when Pease voiced my question on whether these findings meant that Cas9 would not have practical value in human therapies. Even more satisfying was Professor Porteus' response and positive mentality with regards to the issues discussed. It was fascinating to see that genome editing scientists are optimistic about working around the issues of Cas9, as the potential that CRISPR approaches have to offer are not hindered by this obstacle.

It is easy to assume that failure is uncommon in science. Before I took an interest in medical law and bioethics I always thought that failed attempts when testing or creating new medical procedures were at a minimum. However, this is far from the truth, as unsuccessful attempts or issues arising during research and experimentation are not uncommon - especially with regard to genome editing. This radio programme is a refreshing view on what is actually going on in the working life of a genome editing scientist.

Overall, the podcast was unexpectedly easy-to-follow conversation on a not-so-easy subject. The level of detail was well-judged: the audience was provided with enough background information on the practice, the possibilities of it and an insight into its future. I was especially impressed with the well-thought-out questions the host asked, and the order in which he asked them, helping listeners keep up and stay engaged with the conversation.

The fact that the conversation is only seven minutes long means that it is possible to listen to it more than once if so desired. The subject discussed is an interesting one, and with the information and further available sources given, if interested, it is possible for anyone to look further into genome editing.