Can Biotechnology Take the Allergies Out of Cats?
Amy Bitterman, who teaches at Rutgers Law School in Newark, gets enormous pleasure from her three mixed-breed rescue cats, Spike, Dee, and Lucy. To manage her chronically stuffy nose, three times a week she takes Allegra D, which combines the antihistamine fexofenadine with the decongestant pseudoephedrine. Amy's dog allergy is rougher--so severe that when her sister launched a business, Pet Care By Susan, from their home in Edison, New Jersey, they knew Susan would have to move elsewhere before she could board dogs. Amy has tried to visit their brother, who owns a Labrador Retriever, taking Allegra D beforehand. But she began sneezing, and then developed watery eyes and phlegm in her chest.
"It gets harder and harder to breathe," she says.
Animal lovers have long dreamed of "hypo-allergenic" cats and dogs. Although to date, there is no such thing, biotechnology is beginning to provide solutions for cat-lovers. Cats are a simpler challenge than dogs. Dog allergies involve as many as seven proteins. But up to 95 percent of people who have cat allergies--estimated at 10 to 30 percent of the population in North America and Europe--react to one protein, Fel d1. Interestingly, cats don't seem to need Fel d1. There are cats who don't produce much Fel d1 and have no known health problems.
The current technologies fight Fel d1 in ingenious ways. Nestle Purina reached the market first with a cat food, Pro Plan LiveClear, launched in the U.S. a year and a half ago. It contains Fel d1 antibodies from eggs that in effect neutralize the protein. HypoCat, a vaccine for cats, induces them to create neutralizing antibodies to their own Fel d1. It may be available in the United States by 2024, says Gary Jennings, chief executive officer of Saiba Animal Health, a University of Zurich spin-off. Another approach, using the gene-editing tool CRISPR to create a medication that would splice out Fel d1 genes in particular tissues, is the furthest from fruition.
"Our goal was to ensure that whatever we do has no negative impact on the cat."
Customer demand is high. "We already have a steady stream of allergic cat owners contacting us desperate to have access to the vaccine or participate in the testing program," Jennings said. "There is a major unmet medical need."
More than a third of Americans own a cat (while half own a dog), and pet ownership is rising. With more Americans living alone, pets may be just the right amount of company. But the number of Americans with asthma increases every year. Of that group, some 20 to 30 percent have pet allergies that could trigger a possibly deadly attack. It is not clear how many pets end up in shelters because their owners could no longer manage allergies. Instead, allergists commonly report that their patients won't give up a beloved companion.
No one can completely avoid Fel d1, which clings to clothing and lands everywhere cat-owners go, even in schools and new homes never occupied by cats. Myths among cat-lovers may lead them to underestimate their own level of risk. Short hair doesn't help: the length of cat hair doesn't affect the production of Fel d1. Bathing your cat will likely upset it and accomplish little. Washing cuts the amount on its skin and fur only for two days. In one study, researchers measured the Fel d1 in the ambient air in a small chamber occupied by a cat—and then washed the cat. Three hours later, with the cat in the chamber again, the measurable Fel d1 in the air was lower. But this benefit was gone after 24 hours.
For years, the best option has been shots for people that prompt protective antibodies. Bitterman received dog and cat allergy injections twice a week as a child. However, these treatments require up to 100 injections over three to five years, and, as in her case, the effect may be partial or wear off. Even if you do opt for shots, treating the cat also makes sense, since you could protect more than one allergic member of your household and any allergic visitors as well.
An Allergy-Neutralizing Diet
Cats produce much of their Fel d1 in their saliva, which then spreads it to their fur when they groom, observed Nestle Purina immunologist Ebenezer Satyaraj. He realized that this made saliva—and therefore a cat's mouth--an unusually effective site for change. Hens exposed to Fel d1 produce their own antibodies, which survive in their eggs. The team coated LiveClear food with a powder form of these eggs; once in a cat's mouth, the chicken antibody binds to the Fel d1 in the cat's saliva, neutralizing it.
The results are partial: In a study with 105 cats, the level of active Fel d1 in their fur had dropped on average by 47 percent after ten weeks eating LiveClear. Cats that produced more Fel d1 at baseline had a more robust response, with a drop of up to 71 percent. A safety study found no effects on cats after six months on the diet. "Our goal was to ensure that whatever we do has no negative impact on the cat," Satyaraj said. Might a dogfood that minimizes dog allergens be on the way? "There is some early work," he said.
A Vaccine
This is a year when vaccines changed the lives of billions. Saiba's vaccine, HypoCat, delivers recombinant Fel d1 and the coat from a plant virus (the Cucumber mosaic virus) without any vital genetic information. The viral coat serves as a carrier. A cat would need shots once or twice a year to produce antibodies that neutralize Fel d1.
HypoCat works much like any vaccine, with the twist that the enemy is the cat's own protein. Is that safe? Saiba's team has followed 70 cats treated with the vaccine over two years and they remain healthy. Again the active Fel d1 doesn't disappear but diminishes. The team asked 10 people with cat allergies to report on their symptoms when they pet their vaccinated cats. Eight of them could pet their cat for nearly a half hour before their symptoms began, compared with an average of 17 minutes before the vaccine.
Jennings hopes to develop a HypoDog shot with a similar approach. However, the goal would be to target four or five proteins in one vaccine, and that increases the risk of hurting the dog. In the meantime, allergic dog-lovers considering an expensive breeder dog might think again: Independent research does not support the idea that any breed of dog produces less dander in the home. In fact, one well-designed study found that Spanish water dogs, Airedales, poodles and Labradoodles--breeds touted as hypo-allergenic--had significantly more of the most common allergen on their coat than an ordinary Lab and the control group.
Gene Editing
One day you might be able to bring your cat to the vet once a year for an injection that would modify specific tissues so they wouldn't produce Fel d1.
Nicole Brackett, a postdoctoral scientist at Viriginia-based Indoor Biotechnologies, which specializes in manufacturing biologics for allergy and asthma, most recently has used CRISPR to identify Fel d1 genetic sequences in cells from 50 domestic cats and 24 exotic ones. She learned that the sequences vary substantially from one cat to the next. This discovery, she says, backs up the observations that Fel d1 doesn't have a vital purpose.
The next step will be a CRISPR knockout of the relevant genes in cells from feline salivary glands, a prime source of Fel d1. Although the company is considering using CRISPR to edit the genes in a cat embryo and possibly produce a Fel d1-free cat, designer cats won't be its ultimate product. Instead, the company aims to produce injections that could treat any cat.
Reducing pet allergens at home could have a compound benefit, Indoor Biotechnologies founder Martin Chapman, an immunologist, notes: "When you dampen down the response to one allergen, you could also dampen it down to multiple allergens." As allergies become more common around the world, that's especially good news.
Have You Heard of the Best Sport for Brain Health?
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
Listen on Apple | Listen on Spotify | Listen on Stitcher | Listen on Amazon | Listen on Google
Here are the promising studies covered in this week's Friday Five:
- Reprogram cells to a younger state
- Pick up this sport for brain health
- Do all mental illnesses have the same underlying cause?
- New test could diagnose autism in newborns
- Scientists 3D print an ear and attach it to woman
Can blockchain help solve the Henrietta Lacks problem?
Science has come a long way since Henrietta Lacks, a Black woman from Baltimore, succumbed to cervical cancer at age 31 in 1951 -- only eight months after her diagnosis. Since then, research involving her cancer cells has advanced scientific understanding of the human papilloma virus, polio vaccines, medications for HIV/AIDS and in vitro fertilization.
Today, the World Health Organization reports that those cells are essential in mounting a COVID-19 response. But they were commercialized without the awareness or permission of Lacks or her family, who have filed a lawsuit against a biotech company for profiting from these “HeLa” cells.
While obtaining an individual's informed consent has become standard procedure before the use of tissues in medical research, many patients still don’t know what happens to their samples. Now, a new phone-based app is aiming to change that.
Tissue donors can track what scientists do with their samples while safeguarding privacy, through a pilot program initiated in October by researchers at the Johns Hopkins Berman Institute of Bioethics and the University of Pittsburgh’s Institute for Precision Medicine. The program uses blockchain technology to offer patients this opportunity through the University of Pittsburgh's Breast Disease Research Repository, while assuring that their identities remain anonymous to investigators.
A blockchain is a digital, tamper-proof ledger of transactions duplicated and distributed across a computer system network. Whenever a transaction occurs with a patient’s sample, multiple stakeholders can track it while the owner’s identity remains encrypted. Special certificates called “nonfungible tokens,” or NFTs, represent patients’ unique samples on a trusted and widely used blockchain that reinforces transparency.
Blockchain could be used to notify people if cancer researchers discover that they have certain risk factors.
“Healthcare is very data rich, but control of that data often does not lie with the patient,” said Julius Bogdan, vice president of analytics for North America at the Healthcare Information and Management Systems Society (HIMSS), a Chicago-based global technology nonprofit. “NFTs allow for the encapsulation of a patient’s data in a digital asset controlled by the patient.” He added that this technology enables a more secure and informed method of participating in clinical and research trials.
Without this technology, de-identification of patients’ samples during biomedical research had the unintended consequence of preventing them from discovering what researchers find -- even if that data could benefit their health. A solution was urgently needed, said Marielle Gross, assistant professor of obstetrics, gynecology and reproductive science and bioethics at the University of Pittsburgh School of Medicine.
“A researcher can learn something from your bio samples or medical records that could be life-saving information for you, and they have no way to let you or your doctor know,” said Gross, who is also an affiliate assistant professor at the Berman Institute. “There’s no good reason for that to stay the way that it is.”
For instance, blockchain could be used to notify people if cancer researchers discover that they have certain risk factors. Gross estimated that less than half of breast cancer patients are tested for mutations in BRCA1 and BRCA2 — tumor suppressor genes that are important in combating cancer. With normal function, these genes help prevent breast, ovarian and other cells from proliferating in an uncontrolled manner. If researchers find mutations, it’s relevant for a patient’s and family’s follow-up care — and that’s a prime example of how this newly designed app could play a life-saving role, she said.
Liz Burton was one of the first patients at the University of Pittsburgh to opt for the app -- called de-bi, which is short for decentralized biobank -- before undergoing a mastectomy for early-stage breast cancer in November, after it was diagnosed on a routine mammogram. She often takes part in medical research and looks forward to tracking her tissues.
“Anytime there’s a scientific experiment or study, I’m quick to participate -- to advance my own wellness as well as knowledge in general,” said Burton, 49, a life insurance service representative who lives in Carnegie, Pa. “It’s my way of contributing.”
Liz Burton was one of the first patients at the University of Pittsburgh to opt for the app before undergoing a mastectomy for early-stage breast cancer.
Liz Burton
The pilot program raises the issue of what investigators may owe study participants, especially since certain populations, such as Black and indigenous peoples, historically were not treated in an ethical manner for scientific purposes. “It’s a truly laudable effort,” Tamar Schiff, a postdoctoral fellow in medical ethics at New York University’s Grossman School of Medicine, said of the endeavor. “Research participants are beautifully altruistic.”
Lauren Sankary, a bioethicist and associate director of the neuroethics program at Cleveland Clinic, agrees that the pilot program provides increased transparency for study participants regarding how scientists use their tissues while acknowledging individuals’ contributions to research.
However, she added, “it may require researchers to develop a process for ongoing communication to be responsive to additional input from research participants.”
Peter H. Schwartz, professor of medicine and director of Indiana University’s Center for Bioethics in Indianapolis, said the program is promising, but he wonders what will happen if a patient has concerns about a particular research project involving their tissues.
“I can imagine a situation where a patient objects to their sample being used for some disease they’ve never heard about, or which carries some kind of stigma like a mental illness,” Schwartz said, noting that researchers would have to evaluate how to react. “There’s no simple answer to those questions, but the technology has to be assessed with an eye to the problems it could raise.”
To truly make a difference, blockchain must enable broad consent from patients, not just de-identification.
As a result, researchers may need to factor in how much information to share with patients and how to explain it, Schiff said. There are also concerns that in tracking their samples, patients could tell others what they learned before researchers are ready to publicly release this information. However, Bogdan, the vice president of the HIMSS nonprofit, believes only a minimal study identifier would be stored in an NFT, not patient data, research results or any type of proprietary trial information.
Some patients may be confused by blockchain and reluctant to embrace it. “The complexity of NFTs may prevent the average citizen from capitalizing on their potential or vendors willing to participate in the blockchain network,” Bogdan said. “Blockchain technology is also quite costly in terms of computational power and energy consumption, contributing to greenhouse gas emissions and climate change.”
In addition, this nascent, groundbreaking technology is immature and vulnerable to data security flaws, disputes over intellectual property rights and privacy issues, though it does offer baseline protections to maintain confidentiality. To truly make a difference, blockchain must enable broad consent from patients, not just de-identification, said Robyn Shapiro, a bioethicist and founding attorney at Health Sciences Law Group near Milwaukee.
The Henrietta Lacks story is a prime example, Shapiro noted. During her treatment for cervical cancer at Johns Hopkins, Lacks’s tissue was de-identified (albeit not entirely, because her cell line, HeLa, bore her initials). After her death, those cells were replicated and distributed for important and lucrative research and product development purposes without her knowledge or consent.
Nonetheless, Shapiro thinks that the initiative by the University of Pittsburgh and Johns Hopkins has potential to solve some ethical challenges involved in research use of biospecimens. “Compared to the system that allowed Lacks’s cells to be used without her permission, Shapiro said, “blockchain technology using nonfungible tokens that allow patients to follow their samples may enhance transparency, accountability and respect for persons who contribute their tissue and clinical data for research.”
Read more about laws that have prevented people from the rights to their own cells.