Study Shows COVID-19 Virus Uses Nanotubes to "Hijack" the Brain

Researchers at the Institut Pasteur in Paris, France have found the COVID-19 virus enters the brain through nanotubes to cause debilitating neurologic symptoms. The study was conducted in collaboration with CNRS laboratories and published in Science Advances.

The strange neurological effects of acute and long COVID have become a topic of debate as the pandemic wanes on. Many people that became infected long ago are still griping with memory impairment, sleep complications, sensory changes, concentration issues and a general brain fog-like state beyond the initial infection stage.

Early evidence showed traces of the virus’ genetic material in the brain, but the route that the virus traveled was unknown. Scientists and physicians alike have sought answers as to how the virus enters the brain, despite the fact that neurons in the brain lack the receptors that the virus needs for binding.

The COVID-19 virus typically seeks out and binds to the ACE2 receptor on human cells, which are present in the lungs and respiratory tract. The research team explored the possibility that the virus might be entering the brain via nanotubes to cause the notorious neurologic symptoms over an extended period of time.

Chiara Zurzolo, who serves as head of the Institut Pasteur’s Membrane Traffic and Pathogenesis Unit, explained the team’s hypothesis.

"Nanotubes can be seen as tunnels with a road on top, which enable the infection of nonpermissive cells like neurons but also facilitate the spread of infection between permissive cells."

To dig into this possibility, in vitro cultures of human neurons were used, along with the high-resolution abilities of the Titan Krios microscope at the Institut Pasteur’s NanoImaging Core Facility. This approach showed that healthy neurons can become infected by COVID-19 positive neurons. Not only were areas of the nanotubes identified were heavily populated by the virus, but the outside surfaces of these nanotubes appear to host the virus.

This detail suggests that the COVID-19 virus might induce the formation of the nanotubes to open up travel channels for the virus to reach the brain. Importantly, the nanotubules are not regulated by the immune system, giving the virus ample opportunity to make a home in an unlucky individual’s brain.

The U.S. Centers for Disease Control and Prevention (CDC) published new guidance regarding long COVID, or post-COVID conditions, in early July. According to the guidance, symptoms can last weeks to years after the initial infection. People who have not been vaccinated or experienced a severe case of COVID-19 initially are more likely to experience long-term effects. Notably, the CDC explained that the organization is still working to understand how post-COVID conditions develop. This new data might lend insight as government officials attempt to preserve the public’s general health.

As BioSpace previously reported, over half of all COVID-19 diagnoses will result in long COVID symptoms. Most organ systems are impacted by the long-term condition. However, the work conducted at the Institut Pasteur and elsewhere could lead to providing relief sooner than expected.

Among the newest developments, a late-stage clinical study for PureTech’s LYT-100 as a treatment for long COVID is underway. Data from Aviv Clinics suggests that patients with long COVID might benefit from hyperbaric oxygen therapy, namely the neurologic effects.

A Phase IIa clinical trial for Axcella Therapeutic’s long COVID treatment is expected to yield results in early 2023. In summation, with new data explaining the mechanisms by which COVID-19 wreaks havoc on the human body and possible treatments to combat these effects, there is more hope than ever for ending the long-running pandemic.