Science Policy Around the Web October 25th, 2019

By Andrew Wright BSc

Image by Arek Socha from Pixabay 

NIH and Gates Foundation lay out ambitious plan to bring gene-based treatments for HIV and sickle cell disease to Africa

Following the launch of an initiative to boost gene therapy treatments of sickle cell disease last month, the National Institutes of Health (NIH) and the Bill and Melinda Gates foundation have announced a joint funding agreement of at least $100 million over the next four years to expedite a cure for both sickle cell disease and HIV and make it available in Africa. 

The current medical intervention for sickle cell disease is a bone marrow transplant, a treatment that is limited by the availability of genetically compatible donors and can be risky for adult patients. This new partnership aims to build on funding towards more effective treatments that are less restricted and more cost effective. While genetic intervention is being used in a limited clinical setting, it is still necessary to destroy a patient’s stem-cells via chemotherapy before reintroducing the patient’s genetically modified ones. Using burgeoning gene-editing techniques such as CRISPR, researchers for this initiative hope to modify targeted genes with a process more similar to a blood transfusion using replication-deficient viruses or nanoparticles to carry the molecular tools to where they need to be. This should theoretically make treatments much less expensive and more available to regions that have limited medical infrastructure and a high incidence of sickle cell disease such as sub-Saharan Africa. 

Since there is also a high incidence of HIV in sub-Saharan Africa, this initiative also aims to tackle HIV in the region using similar techniques. The current standard for treating HIV is anti-retroviral therapy, which can allow patients to live a normal life, but also must be taken every day, is expensive ($429-$10,896 per month), and does not eliminate the disease. The drive behind genetic intervention strategies comes from serendipitous case-studies when two men were cured of HIV following stem cell transplants that intentionally had white-blood cells with a weakened protein to treat their blood cancers. The NIH-Gates funding initiative will focus on strategies to weaken these proteins (called CCR5 receptors) and to directly destroy HIV genetic material.

(Jon Cohen, Science)

Evidence links poliolike disease in children to a common type of virus

Since 2014 more than 570 children have experienced a condition known as acute flaccid myelitis (AFM) where some suddenly lost limb control, had trouble swallowing or breathing, or ended up paralyzed. These symptoms routinely followed symptoms of a common cold, like a runny nose or fever. Up until now, the route cause behind AFM was not well understood, but recent studies of patients’ spinal fluid suggest the culprit is enterovirus. Infections from enteroviruses are common and rarely cause severe symptoms (although they can cause respiratory illness in asthmatic populations). 

Previous studies into the cause of AFM had examined enterovirus but found no trace of it in the central nervous system, where it would need to be in order to lead to loss of motor control. In the most recent study conducted by the University of California San Francisco, researchers sampled for elevated levels of antibodies in the central nervous system rather than the virus itself. They found that 69% of AFM patients had elevated antibodies against enteroviruses. There are still questions as to why only some children experience AFM when infected by enterovirus when most only experience typical symptoms.

Unfortunately, enterovirus-AFM is currently untreatable beyond post-infection physical therapy, although the lead author of the study suggests that immunoglobin therapy may help reduce the worst symptoms. Ultimately, the only way to completely prevent enterovirus-AFM infections, referred to by some as ”the new polio“,  will be a vaccine.

(Kelly Servick, Science)