Amber Freed and Maxwell near their home in Denver, Colorado.
Getting the diagnosis took months of painful, invasive procedures, as well as fighting with the health insurance to get the genetic testing approved. Finally, in June 2018, doctors at the Children's Hospital Colorado gave the Freeds their son's diagnosis—a genetic mutation so rare it didn't even have a name, just a bunch of letters jammed together into a word SLC6A1—same as the name of the mutated gene. The mutation, with only 40 cases known worldwide at the time, caused developmental disabilities, movement and speech disorders, and a debilitating form of epilepsy.
The doctors didn't know much about the disorder, but they said that Maxwell would also regress in his development when he turned three or four. They couldn't tell how long he would live. "Hopefully you would become an expert and educate us about it," they said, as they gave Freed a five-page paper on the SLC6A1 and told her to start calling scientists if she wanted to help her son in any way. When she Googled the name, nothing came up. She felt horrified. "Our disease was too rare to care."
Freed's husband, a 6'2'' college football player broke down in sobs and she realized that if anything could be done to help Maxwell, she'd have be the one to do it. "I understood that I had to fight like a mother," she says. "And a determined mother can do a lot of things."
The Freed family.
Courtesy Amber Freed
She quit her job as an equity analyst the day of the diagnosis and became a full-time SLC6A1 citizen scientist looking for researchers studying mutations of this gene. In the wee hours of the morning, she called scientists in Europe. As the day progressed, she called researchers on the East Coast, followed by the West in the afternoon. In the evening, she switched to Asia and Australia. She asked them the same question. "Can you help explain my gene and how do we fix it?"
Scientists need money to do research, so Freed launched Milestones for Maxwell fundraising campaign, and a SLC6A1 Connect patient advocacy nonprofit, dedicated to improving the lives of children and families battling this rare condition. And then it became clear that the mutation wasn't as rare as it seemed. As other parents began to discover her nonprofit, the number of known cases rose from 40 to 100, and later to 400, Freed says. "The disease is only rare until it messes with the wrong mother."
It took one mother to find another to start looking into what's happening inside Maxwell's brain. Freed came across Jeanne Paz, a Gladstone Institutes researcher who studies epilepsy with particular interest in absence or silent seizures—those that don't manifest by convulsions, but rather make patients absently stare into space—and that's one type of seizures Maxwell has. "It's like a brief period of silence in the brain during which the person doesn't pay attention to what's happening, and as soon as they come out of the seizure they are back to life," Paz explains. "It's like a pause button on consciousness." She was working to understand the underlying biology.
To understand how seizures begin, spread and stop, Paz uses optogenetics in mice. From words "genetic" and "optikós," which means visible in Greek, the optogenetics technique involves two steps. First, scientists introduce a light-sensitive gene into a specific brain cell type—for example into excitatory neurons that release glutamate, a neurotransmitter, which activates other cells in the brain. Then they implant a very thin optical fiber into the brain area where they forged these light-sensitive neurons. As they shine the light through the optical fiber, researchers can make excitatory neurons to release glutamate—or instead tell them to stop being active and "shut up". The ability to control what these neurons of interest do, quite literally sheds light onto where seizures start, how they propagate and what cells are involved in stopping them.
"Let's say a seizure started and we shine the light that reduces the activity of specific neurons," Paz explains. "If that stops the seizure, we know that activating those cells was necessary to maintain the seizure." Likewise, shutting down their activity will make the seizure stop.
Freed reached out to Paz in 2019 and the two women had an instant connection. They were both passionate about brain and seizures research, even if for different reasons. Freed asked Paz if she would study her son's seizures and Paz agreed.
To do that, Paz needed mice that carried the SLC6A1 mutation, so Freed found a company in China that created them to specs. The company replaced a mouse SLC6A1 gene with a human mutated one and shipped them over to Paz's lab. "We call them Maxwell mice," Paz says, "and we are now implanting electrodes into them to see which brain regions generate seizures." That would help them understand what goes wrong and what brain cells are malfunctioning in the SLC6A1 mice—and help scientists better understand what might cause seizures in children.
Bred to carry SLC6A1 mutation, these "Maxwell mice" will help better understand this debilitating genetic disease. (These mice are from Vanderbilt University, where researchers are also studying SLC6A1.)
Courtesy Amber Freed
This information—along with other research Amber is funding in other institutions—will inform the development of a novel genetic treatment, in which scientists would deploy a harmless virus to deliver a healthy, working copy of the SLC6A1 gene into the mice brains. They would likely deliver the therapeutic via a spinal tap infusion, and if it works and doesn't produce side effects in mice, the human trials will follow.
In the meantime, Freed is raising money to fund other research of various stop-gap measures. On April 22, 2021, she updated her Milestone for Maxwell page with a post that her nonprofit is funding yet another effort. It is a trial at Weill Cornell Medicine in New York City, in which doctors will use an already FDA-approved drug, which was recently repurposed for the SLC6A1 condition to treat epilepsy in these children. "It will buy us time," Freed says—while the gene therapy effort progresses.
Freed is determined to beat SLC6A1 before it beats down her family. She hopes to put an end to this disease—and similar genetic diseases—once and for all. Her goal is not only to have scientists create a remedy, but also to add the mutation to a newborn screening panel. That way, children born with this condition in the future would receive gene therapy before they even leave the hospital.
"I don't want there to be another Maxwell Freed," she says, "and that's why I am fighting like a mother." The gene therapy trial still might be a few years away, but the Weill Cornell one aims to launch very soon—possibly around Mother's Day. This is yet another milestone for Maxwell, another baby step forward—and the best gift a mother can get.
Biochemist Longxing Cao is working with colleagues at the University of Washington on promising research to disable infectious coronavirus in a person's nose.
This may sounds like science fiction, but several research groups are already working on such trickster coronavirus drugs, with some candidates close to clinical trials and possibly even becoming available late this year. The teams began working on them when the pandemic arrived, and continued in lockdown.
When the pandemic first hit and the state of California issued a lockdown order on March 16, postdoctoral researchers Anum and Jeff Glasgow found themselves stuck at home with nothing to do. The two scientists who study bioengineering felt that they were well equipped to research molecular ways of disabling coronavirus's cell-penetrating spike protein, but they could no longer come to their labs at the University of California San Francisco.
"We were upset that no one put us in the game," says Anum Glasgow. "We have a lot of experience between us doing these types of projects so we wanted to contribute." But they still had computers so they began modeling the potential virus-disabling proteins in silico using Robetta, special software for designing and modeling protein structures, developed and maintained by University of Washington biochemist David Baker and his lab.
"We saw some imperfections in that lock and key and we created something better. We made a 10 times tighter adhesive."
The SARS-CoV-2 virus that causes Covid-19 uses its surface spike protein to bind on to a specific receptor on human cells called ACE2. Unfortunately for humans, the spike protein's molecular shape fits the ACE2 receptor like a well-cut key, making it very successful at breaking into our cells. But if one could design a molecular ACE2-mimic to "trick" the virus into latching onto it instead, the virus would no longer be able to enter cells. Scientists call such mimics receptor traps or inhibitors, or blockers. "It would block the adhesive part of the virus that binds to human cells," explains Jim Wells, professor of pharmaceutical chemistry at UCSF, whose lab took part in designing the ACE2-receptor mimic, working with the Glasgows and other colleagues.
The idea of disabling infectious or inflammatory agents by tricking them into binding to the targets' molecular look-alikes is something scientists have tried with other diseases. The anti-inflammatory drugs commonly used to treat autoimmune conditions, including rheumatoid arthritis, Crohn's disease and ulcerative colitis, rely on conceptually similar molecular mechanisms. Called TNF blockers, these drugs block the activity of the inflammatory cytokines, molecules that promote inflammation. "One of the biggest selling drugs in the world is a receptor trap," says Jeff Glasgow. "It acts as a receptor decoy. There's a TNF receptor that traps the cytokine."
In the recent past, scientists also pondered a similar look-alike approach to treating urinary tract infections, which are often caused by a pathogenic strain of Escherichia coli. An E. coli bacterium resembles a squid with protruding filaments equipped with proteins that can change their shape to form hooks, used to hang onto specific sugar molecules called ligands, which are present on the surface of the epithelial cells lining the urinary tract.
A recent study found that a sugar-like compound that's structurally similar to that ligand can play a similar trick on the E. Coli. When administered in in sufficient amounts, the compound hooks the bacteria on, which is then excreted out of the body with urine. The "trickster" method had been also tried against the HIV virus, but it wasn't very effective because HIV has a high mutation rate and multiple ways of entering human cells.
But the coronavirus spike protein's shape is more stable. And while it has a strong affinity for the ACE2 receptors, its natural binding to these receptors isn't perfect, which allowed the UCSF researchers to design a mimic with a better grip. "We saw some imperfections in that lock and key and we created something better," says Wells. "We made a 10 times tighter adhesive." The team demonstrated that their traps neutralized SARS-CoV-2 in lab experiments and published their study in the Proceedings of the National Academy of Sciences.
Baker, who is the director of the Institute for Protein Design at the University of Washington, was also devising ACE2 look-alikes with his team. Only unlike the UCSF team, they didn't perfect the virus-receptor lock and key combo, but instead designed their mimics from scratch. Using Robetta, they digitally modeled over two million proteins, zeroed-in on over 100,000 potential candidates and identified a handful with a strong promise of blocking SARS-CoV-2, testing them against the virus in human cells. Their design of the miniprotein inhibitors was published in the journal Science.
Biochemist David Baker, pictured in his lab at the University of Washington.
UW
The concept of the ACE2 receptor mimics is somewhat similar to the antibody plasma, but better, the teams explain. Antibodies don't always coat all of the virus's spike proteins and sometimes don't bind perfectly. By contrast, the ACE2 mimics directly compete with the virus's entry mechanism. ACE2 mimics are also easier and cheaper to make, researchers say.
Antibodies, which are long protein chains, must be grown inside mammalian cells, which is a slow and costly process. As drugs, antibody cocktails must be kept refrigerated. On the contrary, proteins that mimic ACE2 receptors are smaller and can be produced by bacteria easily and inexpensively. Designed to specs, these proteins don't need refrigeration and are easy to store. "We designed them to be very stable," says Baker. "Our computation design tries to come up with the stable proteins that have the desired functions."
That stability may allow the team to create an inhaler drug rather than an intravenous one, which would be another advantage over the antibody plasma, given via an IV. The team envisions people spraying the miniprotein solution into their nose, creating a protecting coating that would disable the inhaled virus. "The infection starts from your respiratory system, from your nose," explains Longxing Cao, the study's co-author—so a nasal spray would be a natural way to administer it. "So that you can have it like a layer, similar to a mask."
As the virus evolves, new variants are arising. But the teams think that their ACE2 protein mimics should work on the new variants too for several reasons. "Since the new SARS-CoV-2 variants still use ACE2 for their cell entry, they will likely still be susceptible to ACE2-based traps," Glasgow says.
Cao explains that their approach should work too because most of the mutations happen outside the ACE2 binding region. Plus, they are building multiple binders that can bind to an array of the coronavirus variants. "Our binder can still bind with most of the variants and we are trying to make one protein that could inhibit all the future escape variants," he says.
Baker and Cao hope that their miniproteins may be available to patients later this year. But besides getting the medicine out to patients, this approach will allow researchers to test the computer-modeled mimics end-to-end with an unprecedented speed. That would give humans a leg up in future pandemics or zoonotic disease outbreaks, which remain an increasingly pressing threat due to human activity and climate change.
"That's what we are focused on right now—understanding what we have learned from this pandemic to improve our design methods," says Baker. "So that we should be able to obtain binders like these very quickly when a new pandemic threat is identified."