CRISPR helped to "cut" HIV from the genome of mice

Anna Stavina, XX2 century

Perhaps scientists have managed to take a big step towards finding a remedy that can cure HIV completely – and not just take control of the reproduction of the virus. A group of researchers led by specialists from Temple University managed to "remove" viral DNA from the body of an experimental mouse using CRISPR gene editing technology. CRISPR is a technique that allows you to work directly with the genome by removing and inserting certain fragments.

An attempt to use CRISPR to suppress HIV replication and remove the virus from animal cells was made for the first time. The study used three different animal models, including a "humanized" one – to create it, scientists introduced infected cells of the human immune system into the body of an experimental mouse. The results of the work were published in the publication Molecular Therapy (Yin et al., In Vivo Excision of HIV-1 Virus by SaCas9 and Multiplex Single-Guide RNAs in Animal Models).

The study was led by Kamel Khalili, head of the Temple University Center for Neurovirology, together with colleagues: Associate Professor of the Center for Metabolic Disease Research at Temple University Wenhui Hu and Professor of the Department of Radiology at the University of Pittsburgh Won-Bin Young.

Last year, the same team of researchers already published the results of a study in which HIV DNA was injected into the tissues of rats and mice, and then removed using CRISPR. In the new study, the result was reproduced on three models. Experimental animals from the first group were bred in such a way that their cells already contained viral DNA. Mice from the second group were infected with a special kind of HIV, dangerous for rodents. And finally, mice from the third group, as already mentioned, received an injection of infected human immune cells.

The principle of operation of the new method.

With the help of CRISPR, scientists managed to significantly reduce the amount of expressed viral RNA in various organs and tissues of experimental animals. The amount of viral DNA has also decreased. According to the authors of the work, the results obtained indicate that over time the new method can be tested in clinical trials.

Although the new work can definitely be considered as a step forward towards the development of a "cure for HIV", the medical community believes that many more years will pass before such a remedy appears in clinical practice. According to the World Health Organization (WHO), as of the end of 2015, 36.7 million HIV-infected people lived in the world. Since the beginning of the HIV epidemic/About 70 million people were infected with the AIDS virus, more than 35 million died.

Modern antiretroviral drugs are able to reduce the viral load to an almost undetectable level. Thanks to this, patients feel normal and can live a full life. However, the virus persists in the tissues of the body – and becomes active if treatment is stopped. That is why the search is now actively underway for a means that can completely remove the virus from the body, and not just make its presence invisible. CRISPR genome editing technology is a relatively new tool, it appeared about 5 years ago. To introduce it into the clinical practice of HIV treatment – if this approach proves its effectiveness – it will first be necessary to make the CRISPR technology itself more accessible. However, according to experts from the Institute for Finding a Cure for HIV of the American AIDS Research Foundation (amfAR Institute for HIV Cure Research), the goal is worth the effort.

In the near future, a group of scientists led by Khalili plans to test a new technique on primates whose DNA is much closer to human. Khalili and his colleagues are currently preparing to launch this study.

"I think CRISPR and similar tools are completely changing medicine. They can give us new ways to treat a variety of diseases: HIV infection, cancer, genetic diseases. I believe that we will get huge benefits from these technologies," he said Khalili.

Portal "Eternal youth" http://vechnayamolodost.ru  10.05.2017