Viruses use the DNA of their hosts to help themselves reproduce. Bacteria have counter-attacked viruses by grabbing some of the DNA from viruses and using this to identify them and kill them back. That as an oversimplified description of an eons old arms race between viruses and bacteria.

Among the DNA sequences co-opted by bacteria is the famous gene-frag-family known as CRISPR. You’ve heard of it, and you probably know what it does. Briefly, genetic scientists can use the innate power of CRISPR to manipulate other DNA to “repair” or modify in situ DNA sequences in living organisms. Got a genetic disease? No problem. We get the good genetic sequence, and then use the CRISPR based technology to replace all your bad DNA with the good DNA.

Now, of course, that doesn’t really work this way, and CRISPR technology has had fairly limited success so far. But there have been successes, and CRISPR is generally regarded as the Next Great Hope in the future of genetic therapy.

But now there may be a problem. Among the bacteria that use a CRISPER sort of sequence are two that are fairly nasty and common human pathogens. These are Staphylococcus aureus and Streptococcus pyogenes. In fact, the specific CRISPER sequences that genetic scientists use to do the CRISPR thing, come from these specific bacteria.

So, think about this for a moment. If CRISPER is used by bacteria to do any of their dirty work, and the bacteria are common human pathogens, is it possible that some humans have built up an immunity to the CRISPER sequences, perhaps putting them off limits for future CRISPR therapy? Continue reading A Possible Problem with CRISPR →