Recently there has been an increasing amount of research attempting to control CRISPR gene-editing systems. These systems are found in many types of bacteria as a defense against viruses. The researchers see these gene-editing systems as potential treatment to fight human disease. Hongiian Wang and associates at the University of Wuhan in China presented the findings of their research in the journal PLOS Biology.

CRISPR offers many options for detecting, manipulating, and imaging RNA or DNA sequences of various organisms. CRISPR has become a most powerful gene editing tool.

The Paradigm Continues

Gene editing, also known as genome engineering, is a revolutionary technique that modifies DNA to treat disease and improve human health. The DNA process is aided by sgRNA that guides Cas9 and other Cas-proteins during gene editing. The systems depend upon these CRISPR-associated (Cas) proteins. Cas9 and Cas12a are the most common forms with each having its own strength and weakness. CRISPR arrays are genes that convert Cas proteins and provide the machinery necessary to acquire fragments of foreign DNA called spacers that target invaders. Spacers are part of the process that makes guide RNA.

An Idea Needing a Solution

The researchers intend to combine the CRISPR proteins inside a non-disease-causing virus (non-pathogenic) that would transport the proteins to the target cells. At that location they could modify DNA sequences and treat the disease. The issue that must be resolved is the size of the adeno-associated virus that cannot accommodate Cas 12a proteins. Professor Wang and his associates have identified a smaller version of Cas 12a called EbCas12a. It is a natural occurrence in Erysipelotrichia bacteria.

The Virus Reduced Cholesterol

The team found that enEbCas12a can be modified for use in adeno-associated gene therapy. The virus was administered to mice that had high cholesterol. When they examined the mice 30 days later, the team discovered a substantial reduction in levels of cholesterol in the mice who were treated as opposed to untreated mice. Most likely there will be continued research to determine if enEbCas12a has the potential for use against human disease. However, it seems that the adeno-associated virus has the potential to deliver Cas12a proteins in gene therapy.

In conclusion the authors added that enEbCas12a plus crRNA may be combined in an AAV system for gene editing.