A permanent cure for HIV infection remains elusive due to the virus’s ability to hide away in latent reservoirs. But now, in new research published in the journal Molecular Therapy, scientists at the Lewis Katz School of Medicine (LKSOM)  at Temple University and the University of Pittsburgh show that they can excise HIV DNA from the genomes of living animals to eliminate further infection. They are the first to perform the feat in three different animal models, including a “humanized” model in which mice were transplanted with human immune cells and infected with the virus. The team is the first to demonstrate that HIV-1 replication can be completely shut down and the virus eliminated from infected cells in animals with a powerful gene editing technology known as CRISPR/Cas9. The new work builds on a previous proof-of-concept study that the team published in 2016

“Our new study is more comprehensive,” Dr. Hu said. “We confirmed the data from our previous work and have improved the efficiency of our gene editing strategy. We also show that the strategy is effective in two additional mouse models, one representing acute infection in mouse cells and the other representing chronic, or latent, infection in human cells.”

In the new study, the team genetically inactivated HIV-1 in transgenic mice, reducing the RNA expression of viral genes by roughly 60 to 95 percent, confirming their earlier findings. They then tested their system in mice acutely infected with EcoHIV, the mouse equivalent of human HIV-1.

“During acute infection, HIV actively replicates,” Dr. Khalili explained. “With EcoHIV mice, we were able to investigate the ability of the CRISPR/Cas9 strategy to block viral replication and potentially prevent systemic infection.” The excision efficiency of their strategy reached 96 percent in EcoHIV mice, providing the first evidence for HIV-1 eradication by prophylactic treatment with a CRISPR/Cas9 system.

The work was led by Wenhui Hu, MD, PhD, currently Associate Professor in the Center for Metabolic Disease Research  at LKSOM; Kamel Khalili, PhD, Laura H. Carnell Professor and Chair of the Department of Neuroscience, Director of the Center for Neurovirology, and Won-Bin Young, PhD. Dr. Young was Assistant Professor in the Department of Radiology at the University of Pittsburgh School of Medicine at the time of the research. Dr. Young recently joined LKSOM.

Source: https://medicine.temple.edu/

A new gene therapy could eventually provide an alternative treatment for Fuchs’ endothelial corneal dystrophy, a genetic eye disease that affects roughly one in 2,000 people globally. Currently, the only treatment is corneal transplant, a major surgery with associated risks and potential complications.

“When you do a transplant you make a huge difference for that person, but it’s a big deal for the patient with lots of visits, lots of eye drops, lots of co-pays, and if you had a medical treatment that did not require surgery, that would be great,” says Bala Ambati, a research professor at the University of Oregon who led an eight-year study involving the development of the gene therapy. “Not only could it help patients who need a transplant, but it could also help a lot of other people who could have used that (corneal) tissue.”

For the study in the journal eLife, investigators focused on a rare, early-onset version of the disease and carried out the research in mice. They used CRISPR-Cas9, a powerful tool for editing genomes, to knock out a mutant form of a protein that is associated with the disease.

Fuchs’ dystrophy occurs when cells in the corneal layer called the endothelium gradually die off and stressed cells produce structures known as guttae. These cells normally pump fluid from the cornea to keep it clear, but when they die, fluid builds up, the cornea gets swollen, and vision becomes cloudy or hazy.

“We were able to stop this toxic protein expression and study it in a mouse model,” says coauthor Hiro Uehara, a senior research associate in the Ambati lab. “We confirmed that (in mice who received it), our treatment was able to rescue loss of corneal endothelial cells, reduce guttata-like structures, and preserve the corneal endothelial cell pump function.”

Corneal cells are non-reproducing, meaning you’re born with all of the cells you will ever have, Ambati says. One of the challenges of the study involved using CRISPR gene editing technology on such cells, a process that is technically difficult.

Uehara developed an innovative workaround that increases the utility of the CRISPR technology and could eventually lead to treatments for other diseases involving non-reproducing cells, including some neurologic diseases, immune diseases, and certain genetic disorders affecting the joints. The study marks the first time that researchers have applied the technique, called start codon disruption, to non-reproducing cells.

Source: https://accelerate.uoregon.edu/

A Chinese researcher who claims to have created the first gene-edited babies, He Jiankui of the Southern University of Science and Technology (SUST), in Shenzhen, is now facing investigation over whether the experiment broke Chinese laws or regulations. The children have their genomes modified to make them resistant to HIV.

He, who led that effort, later released a video statement in which he said that healthy twin girls, Lulu and Nana, had been born “a few weeks ago.”

He said the girls had been conceived using In vitro fertilization (IVF) but that his team had added “a little protein and some information” to the fertilized eggs. That was a reference to the ingredients of CRISPR, the gene-editing technology he apparently employed to delete a gene called CCR5.

The claim set off a wave of criticism in China and abroad from experts who said the experiment created unacceptable risks for a questionable medical purpose. Feng Zhang, one of the inventors of CRISPR, called for a moratorium on its use in editing embryos for IVF procedures.

Documents connected to the trial named the study’s sponsors as He along with Jinzhou Qin and said it was approved by the ethics committee of HarMoniCare Shenzhen Women and Children’s Hospital.

Source: https://www.technologyreview.com/

Scientists seeking new ways to fight drug-resistant superbugs have mapped the genomes of more than 3,000 bacteria, including samples of a bug taken from Alexander Fleming’s nose and a dysentery-causing strain from a World War One soldier. The DNA of deadly strains of plague, dysentery and cholera were also decoded in what the researchers said was an effort to better understand some of the world’s most dangerous diseases and develop new ways to fight them. The samples from Fleming – the British scientist credited with discovering the first antibiotic, penicillin, in 1928 – were among more than 5,500 bugs at Britain’s National Collection of Type Cultures (NCTC) one of the world’s largest collections of clinically relevant bacteria. The first bacteria to be deposited in the NCTC was a strain of dysentery-causing Shigella flexneri that was isolated in 1915 from a soldier in the trenches of World War One.

“Knowing very accurately what bacteria looked like before and during the introduction of antibiotics and vaccines, and comparing them to current strains, … shows us how they have responded to these treatments,” said Julian Parkhill of Britain’s Wellcome Sanger Institute who co-led the research. “This in turn helps us develop new antibiotics and vaccines.”

Specialists estimate that around 70 percent of bacteria are already resistant to at least one antibiotic that is commonly used to treat them. This has made the evolution of “superbugs” that can evade one or multiple drugs one of the biggest threats facing medicine today. Among the most serious risks are tuberculosis – which infects more than 10.4 million people a year and killed 1.7 million in 2016 alone – and gonorrhea, a sexually transmitted disease that infects 78 million people a year and which the World Health Organization says is becoming almost untreatable.

Source: https://www.reuters.com/