The team at Kobe University used CRISPR/Cas9 to remove two regulatory genes of HIV-1 – which causes 95 percent of HIV infections – within infected human cell lines, and so stop further production of the virus.
'Based on the rapid advances being achieved in CRISPR/Cas9 research, a HIV-1 functional cure may soon be within reach,' the researchers write in their paper published in Scientific Reports.
Although advances have meant that HIV has gone from being a deadly disease to a chronic condition manageable with drug treatment, there is no cure as the virus can sit in dormant reservoirs within cells. It does this by incorporating itself within the chromosomes of a patient's cells. As soon as treatment is stopped, the virus rebounds, and so drug therapy must be lifelong.
The team aimed to stop these viral reservoirs from reactivating and proliferating by using genome editing to target HIV-1 genes, tat and rev, which are crucial for the dormant virus to replicate. This was repeated in each of the six major subtypes of HIV-1.
The method successfully blocked the production of tat and rev proteins, and consequently production of the virus. The team said there were also no off-target effects seen from the genome editing, and it did not affect the survival of the cultured cells.
'These results show that the CRISPR/Cas9 system, by targeting the regulatory genes of HIV-1, tat and rev, is a promising method for treating HIV infection,' said Professor Masanori Kameoka, one of the study authors.
'We now need to investigate how we can selectively introduce a CRISPR/Cas9 system that targets HIV-1 genes into the infected cells of patients. In order to safely and effectively introduce the CRISPR/Cas9 system the vectors must be improved,' said Professor Kameoka. 'We hope this research will provide us with useful information in developing a treatment method that can completely cure the HIV-1 infection.'