Research

Close encounters of the plant protein kind

Bond LSC researchers David Mendoza (left) and Scott Peck (right) are collaborating to develop a new method for studying plant signaling pathways as they happen inside the cell. | photo by Jennifer Lu, Bond LSC

Bond LSC researchers David Mendoza (left) and Scott Peck (right) are collaborating to develop a new method for studying protein signaling pathways inside plant cells. | photo by Jennifer Lu, Bond LSC

By Jennifer Lu | Bond LSC

Sometimes, timing is everything.

That was the case in what led to a new collaboration between the Mendoza and Peck laboratories. The two researchers were recently awarded $48,250 in seed money from the Bond Life Sciences Center to adapt a new technology to the study of signaling pathways in plant cells.

David Mendoza, a Bond LSC researcher and assistant professor of plant sciences who is interested in nutrient uptake in plants, got the idea for the project when he attended the Trace Elements in Biology and Medicine conference in June. There, he kept hearing about an enzyme called BioID used to identify protein interactions in mammalian cells.

“In plants, we have a hard time figuring out how proteins interact with each another to transfer information within the cell,” Mendoza said. BioID could be the key.

BioID works like a spy slipping a small tracker into the coat pocket of every person it encounters, but instead of a tracker, BioID transfers a unique molecular tag onto every protein that comes near. It’s a speedy process, no matter how brief the interaction between BioID and the incoming protein. But once the proteins are tagged, they can be rounded up and identified later, even if they’ve moved elsewhere in the cell.

Scientists can study which proteins interact with their protein of interest by linking BioID to their protein. This lets them track the signals being communicated to and through their protein without disrupting what’s happening inside the cell.

Although BioID has exclusively been used in animal systems, Mendoza talked to the scientist behind BioID to see if it could be used in plants.

Incidentally, BioID has been publicly available for several years but the enzyme was impracticable for plant experiments. It needed a lot of raw material on hand before it could start tagging proteins, much more material than what is normally found within plant cells.

However, research on a more suitable candidate called BioID2 was published just months before the conference. Unlike its predecessor, BioID2 required very little starting material to function in plants.

“Like a lot of things,” Mendoza said, “timing was key.”

When he approached Scott Peck, a colleague at the Bond LSC and professor of biochemistry specializing in plant proteomics, with the news, Peck saw immediate applications for BioID2.

With currently available methods, plant scientists have to look at protein interactions in artificial environments, such as in a test tube or in yeast systems. A real-time protein-tagging method would allow plant scientists to observe signaling pathways in their native environment–the cell–under a variety of conditions.

“It allows the contextual information within the plant to still be present,” Peck said.

For example, with BioID2 the Peck lab, which studies plant resistance to bacteria, could watch how incoming stimuli such as plant pathogens or stress from drought affect overall protein-to-protein interactions within plants, compare these protein interactions across different cell types, or even discover previously unknown protein interactions, he said.

“You know you have a good idea when the other person gets excited right away,” Mendoza said.

Peck also had a suitable model handy in which they could test BioID2 at work, but the two researchers first had to make sure plant cells could produce functional BioID2. Mission accomplished, the next step is to make plants produce BioID2 that is linked to their protein of interest.

“The nice part of this seed grant is it lets us get a jump on some new technology to develop here,” Peck said.

Using BioID2 in plants is an interesting and novel idea, Mendoza said. “For me, that’s enough to try.”

 

This seed funding is one of seven awarded this year at the Bond Life Sciences Center. These awards, which range from $40,000 to $100,000 in funding, foster inter-laboratory collaboration and make possible the development of pilot projects.

 

Building blocks of life in the lab could revolutionize life for us all

NASA, NIH-funded work seeks to understand bio-chemical mechanisms of life on Earth, and among the stars
By Phillip Sitter | Bond LSC

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Donald Burke-Agüero stands in his office in Bond LSC, holding a model of an RNA protein structure. Burke-Agüero studies the bio-chemical functions of RNA, and how those functions might be able to be artificially designed or replicated. | Phillip Sitter, Bond LSC

Any child obsessed with Legos knows the fun of creation bound only by imagination and the size or variety of the blocks within their pile.

For some scientists, that spirit extends into adulthood, but instead of plastic parts they think about arranging blocks of nucleic acids.

Scientists may not be able to create dinosaurs, dragons or mythical sea creatures the way kids with Legos can. Through the manipulation of nucleic acid building blocks though, they may be better able to understand how the processes of life on Earth work, as well as out among the stars.

“I have a lot of fun asking what is possible,” said Donald Burke, a Bond Life Sciences Center investigator who spends his time researching the building blocks of life.

Burke said he has been interested in the origins of life for 40 years, and he has been associated with NASA for about 20 years.

NASA’s interest in understanding the origins of life is pretty straightforward. It wants to know what clues to look for on other worlds to figure out if those planets also support life.

Many of Burke’s previous discoveries at Bond LSC are funded by NASA’s exobiology and evolutionary biology program.

“No, I have not thought of an excuse to fly anything up there. I’ve tried to think ‘which of my experiments would make sense to do in a micro-gravity or zero gravity environment?’” he explained of the prospect of sending some of his work into orbit, with a wry smile.

But, there’s even more to understanding the building blocks of life than looking for bio-chemical signatures out among the stars. Knowing how these parts are put together allows scientists like Burke to understand the origins and processes of Earth’s biology, and, conceivably create chemical and biological processes or even organisms not found in nature in the near future.

 

A quadrillion arrangements of blocks, one arrangement at a time

“Many of the molecules of life are built from strings of amino acids, or nucleotides or other building blocks,” Burke explained. He also noted that these buildings blocks are not just strings, but fold up into three dimensional shapes.

RNA, or ribonucleic acid, stands out as an essential building blocks in the bio-chemical processes of life.

Put simply, RNA is a kind of molecular structure of nucleic acids similar to DNA (deoxyribonucleic acid) that comes in many combinations. These combinations are at the core of every cell, and play a role in coding, decoding, regulating and expressing the basic operating instructions for each cell — its genes.

The molecules we’re talking about are almost unimaginably small. In one test tube, Burke said there can be one quadrillion of them — that’s a one with 15 zeroes after it. Put another way, that’s roughly equivalent to the estimated number of ants that live on Earth.

Burke’s work focuses on the end goal of being able to artificially create original RNA combinations. In what’s known as experimental evolution, “the population of molecules in the tube is evolving as a result of us imposing experimental constraints upon it.”

This artificial synthesis of RNA molecules looks to create random sequences or variations on natural RNA to create new ones non-existent in nature. A second route aims to selectively choose molecules with certain properties, and use them to build altogether new combinations.

“Their string-like properties allow us to copy them, and make more copies, and make more copies, and make more copies. Their shape-like properties allow us to observe the bio-chemical behaviors they may have,” Burke explained how he and other scientists interact with RNA’s structure in the lab.

“I don’t think we know what those limitations are yet,” he said of the capabilities of RNA.

The motivation for wanting to be able to intentionally design RNA molecules is so that it “can do the things we want it to do under the conditions where we want it to do those things,” he explained of the process of the process of selecting RNA sequences for specific properties.

“I want the ones that will bind a tumor cell. I want the ones that will bind a viral protein. I want the ones that will catalyze useful chemical reactions.”

 

RNA’s path to the future following in biology’s footsteps

The National Institutes of Health and other organizations recognize that engineered forms of RNA have the potential to fight diseases, and they have funded Burke’s work.

He has studied RNA that instructs human cells on how to defend themselves from HIV and is now looking at other RNA that interferes with the proteins of the Ebola virus.

The expectation is that such therapeutics would work in conjunction with other treatments. In the future, they could be expanded to help fight other viruses, cancers and other diseases.

RNA could also be used to start, or catalyze, chemical reactions. As Burke explained, catalysts remove barriers to chemical reactions — “they don’t make things happen that wouldn’t otherwise happen, but they speed up the process.”

Synthetic RNA could be used to accelerate removal of toxins from soil or to get the bacteria in our guts to recognize cancerous tumor cells and kick-start an immune response.

But, the future of RNA research may soon reveal a few different Holy Grail moments on its horizon.

One such Holy Grail that Burke said will definitely happen will be observations consistent with the presence of life on other worlds, based on evidence like an atmosphere having certain chemical compositions.

Another likelihood could involve construction of a self-replicating, fully-artificial organism, either created from scratch or reverse-engineered from other organisms.

For those of you already anticipating the plot of a low-budget sci-fi thriller, Burke offered to assuage your fears.

“The notion of it escaping out in the world and taking over Los Angeles is [only] good 1950’s B-movie” material, because the conditions under which this artificial organism would survive would probably be difficult to maintain even in the controlled environment of lab, he said.

Instead of B-movie science, Burke explained that “really, I’m thinking about what kinds of chemistries we want to see take place, and then building the enzymes that would make it possible.”

“Biology has had a few billion years to work on this, but we’re just starting to figure it out.”

Donald Burke-Agüero is a professor of molecular microbiology and immunology and joint professor of biochemistry and biological engineering.

Standing out through saliva

Bond LSC scientist internationally recognized for work on salivary glands and autoimmune disorders
By Phillip Sitter | Bond LSC

You might not think too highly of spit, but you would quickly regret not having any.

People with Sjögren’s syndrome suffer chronic dry mouth and eyes from an overzealous immune system that attacks salivary and tear ducts, causing serious health issues.

Gary Weisman’s research might hold the key to understanding and managing this immune response, leading to effective treatment or even prevention of this ailment.

For this, the International Association of Dental Research, or IADR, awarded him the 2016 Distinguished Scientist Award for Salivary Research. Weisman accepted the award in June at the opening ceremonies of the IADR conference in Seoul, Republic of Korea.

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Gary Weisman stands in his lab in Bond LSC where he studies the cellular mechanisms of auto-immune disease, specifically how the release of ATP from damaged cells signals receptors that trigger an immune response. | Phillip Sitter, Bond LSC

“We want the good, but not the bad,” said Weisman, a Bond Life Sciences Center investigator, of what we ideally want from our immune system’s functions.

Mice with un-checked autoimmune disease of their salivary glands have their glands destroyed. The disease can spread to other secretory organs next. An over-reactive immune system on a civil war-path can extend its damage to cause pancreatic failure and death.

The destruction wrought by Sjögren’s syndrome is self-inflicted, caused by an overreaction of our bodies’ defenses against infection and injury. This is what an autoimmune disease is.

But, our bodies’ immune cellular response team is complicated. Weisman said dozens of different cell types have been isolated and identified as part of the immune system, and he likens the immune system to fire, police and construction services in human society all working together.

While firefighters are meant to prevent further damage from an inferno, sometimes our bodies’ first responders start doing the equivalent of using dynamite to stop the spread of a fire.

In chronic inflammation, that autoimmune response can mean a burning, throbbing, constant pain. The key to a healthy immune response is balance. The balance has to be between containment and repair of damage caused by infection or injury and damage caused by chronic inflammation if that emergency response continues unabated.

Weisman has spent almost 30 years studying how to prevent our bodies’ immune system from over-reacting to threats and causing further harm.

Earlier in his career, Weisman studied how extracellular ATP plays a critical role in immune responses, and how too much of it can cause the over-reaction that leads to tissue destruction in autoimmune diseases. ATP, or adenosine 5’-triphosphate, is the main molecule used for energy in cellular activities inside cells. Weisman was one of the first scientists to study how damaged cells release ATP as a distress signal.

The released ATP signals receptors that “send out the alarm to the fire station” — the body’s immune cells, he said.

Once he understood this, Weisman began to manipulate the actions of released ATP to see how that would affect an immune response.

Mice with salivary gland autoimmune disease got healthy when the released ATP was prevented from activating their receptors on the surface of cells. Preventing the ATP receptors from being activated slowed down and even stopped the advance of autimmune disease.

Conversely, if you prevent the activation of the ATP receptors in lab mice with Alzheimer’s disease they die much more rapidly from the disease, Weisman said, suggesting that activation of immune cells by ATP is beneficial in slowing the progression of this disease.

Alzheimer’s disease and autoimmune diseases such as Sjögren’s syndrome are only some of the inflammatory diseases that Weisman has studied. With each of these diseases, the role of ATP receptors has to be investigated individually, suggesting that Weisman’s work may extend beyond salivary glands and the brain to other parts of the body.

“Our [ATP] receptor is also involved in heart disease,” Weisman said, and he added that other diseases like cystic fibrosis, cancer, lupus and arthritis have inflammatory components, too.

For now, we all fight a losing battle when it comes to our bodies’ management of the immune system. As we and our immune system age, it has the potential to destroy more than it protects and “eventually you could slip over to the dark side and die,” Weisman said.

In the meantime, Weisman said that a better understanding of the immune system could lead to more effective, targeted treatments of chronic inflammation and other autoimmune disorders. This could provide a new approach to control undesirable activation of the immune system beyond the use of with anti-histamines, anti-cytokines and ibuprofen.

Weisman is a Curator’s Distinguished Professor of Biochemistry. He began his salivary gland research at MU 27 years ago with Professor John Turner, before Turner’s retirement. Since then, his research has been continuously funded by the National Institutes of Health, where one of his recent grants was well scored and will likely be extended for another five years.

Finding hope by fixing a gene

Lorson lab publishes research on a new therapeutic path to help treat spinal muscular atrophy
By Phillip Sitter | MU Bond Life Sciences Center

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Erkan Osman shows iImages of neuro-muscular junctions. Osman, a post-doctoral fellow in Chris Lorson’s lab, co-authored research in the journal Molecular Therapy that details work in binding a synthetic nucleic acid to a normally useless motor neuron backup gene to help treat spinal muscular atrophy. | photo by Phillip Sitter, Bond LSC

Imagine you are forced to jump out of an airplane.

Luckily, you find a parachute that even has a backup chute. You leap out of the plane and free-fall.

You pull the cord to open your parachute, but it doesn’t open. Don’t panic, though, you have a backup. But, you pull that cord and nothing happens. Now you face the reality of a death as firm and un-yielding as the ground rushing into your view.

This air disaster mirrors the mechanism and mortal threat posed for people born with the genetic problem that causes spinal muscular atrophy (SMA).

Chris Lorson’s lab at the Bond Life Sciences Center would like to change that situation by making an effective genetic backup to the defective gene that results in SMA. The journal Molecular Therapy, a publication of Nature, recently accepted their findings for publication.

The defect occurs in a specific gene called Survival Motor Neuron (SMN). If the SMN gene is defective because of mutation, this causes a deficiency of the SMN protein it is supposed to produce. Without this protein, the neurons that control muscle movement malfunction. Signals cease to stimulate muscles.

Muscles that are not stimulated atrophy, grow weak and waste away. At first this happens with the skeletal muscles, which leads to loss of motor function for simple activities like walking and swallowing. If it happens with the muscles that control breathing, you die.

News of the disease often presents a devastating prognosis. Infants have it worst; babies diagnosed with SMA only have a life expectancy of two to five years from birth.

Fortunately, our bodies have a sort of backup for the SMN gene, another one called SMN-2. But, like a useless backup parachute for an unlucky skydiver, SMN-2 isn’t actually very good at producing proteins of the quality needed to stave off SMA. It might just be a vestigial trait on its way down the evolutionary drain — it doesn’t even exist in the closest primate relatives of humans.

Discoveries in the Lorson lab look to make the SMN-2 gene an effective backup, and their recent publications indicate that this may be a viable possibility for future SMA treatments.

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Christian Lorson studies the genes that cause SMA when they fail to adequately function. His team’s on a backup gene that greatly extended life expectancy in mouse studies. | photo by Phillip Sitter, Bond LSC

“What we’ve been working on in the lab is a potential therapeutic, and what it does, it’s a large small molecule that is called an antisense oligonucleotide, or ASO,” Lorson said. “And this is something that is essentially a synthetic piece of nucleic acid that is able to go in and bind to a specific sequence within a gene.”

Once bound to SMN-2, the ASO is designed to alter mRNA splicing, “essentially, the editing of a gene,” Lorson said. Speaking in terms akin to products leaving a factory, Lorson said that the attached ASO makes SMN-2 produce good quality proteins, the ones that it wasn’t able to produce before.

In other words, suddenly the backup protein-factory that was making poor-quality products is now pumping out top-of-the-line stuff that will work.

Previous research identified a strong ASO contender to experiment with, and Lorson said current research is about optimizing an ASO to extend survival times in mice with SMA — from just 13 days to five months after only one injection at birth.

Lorson stressed that his lab’s achievement doesn’t promise a fast cure for SMA. He said it is unlikely a single compound will address the full gambit of effects that people with SMA suffer, especially given that people can be identified as having SMA at any time from birth through later in life — often late onset SMA tends to be less severe than diagnosis as an infant.

There’s not yet any single compound treatment for SMA that has been approved by the Food and Drug Administration, Lorson said, so he cautions against getting hopes up of for a revolutionary treatment for SMA coming onto the market soon — “Near future but not tomorrow.”

He acknowledged, though, that “from a research perspective, things seem to be moving at lightning speed, but if you are a patient or a family member, things can never go fast enough, so I think there’s a realized sense of urgency, whether or not it’s for patients who don’t have the disease yet, are not born, or for patients who have had the disease for a decade and are wondering when their opportunity would come.”

Lorson’s work is funded in part by Cure SMA, FightSMA and the Gwendolyn Strong foundations. Erkan Osman, a post-doctoral fellow in Lorson’s lab and the first author on the most recent paper, won the emerging investigator award from FightSMA and Gwendolyn Strong in 2015.

How does Zika move from mother to child?

Scientists use placental cells in lab to study virus
By Phillip Sitter | MU Bond Life Sciences Center

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Megan Sheridan, an MU grad student, removes the base solution from a demonstrated sample of stem cells that will be grown into placental cells for study of Zika virus. Within four days of exposure to the correct hormones, the stem cells express genes of placental cells, and within another day start producing placental hormones. The cells are infected with Zika at day four to ensure maximum measurable interaction, as the stem cells naturally die in culture after about ten days. | photo by Phillip Sitter, Bond LSC

Scientists believe they have a better way to study how Zika virus can spread from a pregnant mother to her fetus — and their technique doesn’t even involve observations of babies in the womb or post-natal examinations.

“As soon as we heard about Zika, everybody’s light bulbs turned on,” said Megan Sheridan, a graduate student at the University of Missouri Bond Life Sciences Center.

Sheridan works in the lab of  Toshihiko Ezashi at Bond LSC, and she, in turn, is part of a cross-campus team researching Zika with R. Michael Roberts, Alexander Franz, Danny Schust and Ezashi.

Roberts’ lab studies pluripotent stem cells — progenitor cells which can develop into any other type of cell in the body.

“We use the proper signals to drive stem cells to become like placental cells,” Sheridan explained. With this capability to stimulate stem cells with growth hormones and inhibitors at opportune moments, Roberts’ researchers realized they could create enough placental cells to create an environment similar to that of a womb in very early stages of pregnancy.

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Megan Sheridan sits in front of a demonstration of her work with pluripotent stem cells. Sheridan is a graduate student who works in Toshihiko Ezashi’s lab, where she produces cells with placental characteristics from the stem cells in order to study placenta interaction with Zika virus. | photo by Phillip Sitter, Bond LSC

This is something which Sheridan thinks hasn’t been done before in regards to studying placental interaction with Zika. Their technique could give a look into the first trimester, when epidemiological studies say a fetus is most susceptible to infection.

Roberts’ lab is trying to understand the placental barrier’s vulnerability to Zika virus in its early stage of pregnancy. During this time, an infection could occur even before the mother is aware she is pregnant.

If the lab uses their technique to understand how Zika virus enters placental cells, then potentially they could also learn how to strengthen the placenta as a barrier to Zika and make it a first line of defense against infection of the fetus in the womb. If developing babies don’t get infected with Zika, then they won’t suffer the consequences of birth defects.

One such defect is microcephaly where a baby is born with a smaller than expected head, which may in turn be a sign that their brain has not fully developed. While infection with Zika virus is rarely fatal or otherwise severe in itself — many people don’t even develop symptoms — birth defects like microcephaly could cause further developmental problems like delays in learning how to speak and walk, intellectual disabilities, difficulty swallowing and problems with hearing and vision, according to global health organizations.

Microcephaly only became a widely documented effect of Zika after a particular strain surged across South and Central America with the infected mosquitoes that carry it, Sheridan explained, but this may be in part because previous Zika infections and outbreaks were themselves poorly documented.

While birth defects caused by Zika have drawn much media attention as the disease has spread northward through our hemisphere from Brazil, studies focusing on infection in the womb have only used placental material that has come to term. This may not be the most accurate way to see how the placenta gets infected in the first place early in pregnancy.

The pathway of Zika virus infection in lab mice isn’t really comparable to human infection, because mice aren’t infected with this virus naturally. Only lab mice that have had their genomes altered to be able to acquire the virus have susceptibility to the infection that can be modeled.

Roberts’ lab is currently working with the African strain of Zika and obtained strains from Southeast Asia and Central America recently. There’s about a 99 percent genetic similarity across strains, Sheridan said.

Zika virus was first discovered in Africa in Uganda in 1947, according to the Centers for Disease Control and Prevention. The first human case was documented in 1952, and subsequent outbreaks also occurred in Southeast Asia and the Pacific Islands. The Pan American Health Organization issued an alert about the confirmed arrival of the virus in Brazil in May 2015.

The lab has completed Zika infections of some of their stem cell-produced placental cells. Sheridan reassured that even though the lab works with live viruses, Zika is not airborne, and none of their work involves mosquitoes.

Roberts’ lab submitted one grant application earlier this year to the National Institutes of Health for funding for their research. While that application was denied, Sheridan said that they have a lot more preliminary data now and are hoping to submit a revised grant soon.

She said that their original work was “highly scored, but the funding level is still low,” meaning that obtaining funds for research into Zika virus is highly competitive nationally.

Legislation to fund more efforts into studying and preventing transmission of Zika virus is caught in congressional gridlock, according to The New York Times and other media outlets.

In the mean time, as the Roberts lab prepares its next grant application submission, Sheridan said of her efforts that she is “working hard to make progress on the project as quickly as possible.”

Please visit the CDC’s dedicated page for more information on Zika virus — including advice for travellers and pregnant women, description of symptoms and treatment, steps you can take to control mosquitoes and prevent other means of transmission of the virus and more background on the history and effects of the disease.

MU Metabolomics Center

Professor Lloyd W. Sumner introduces University of Missouri Metabolomics Center. The new center provides leading-edge equipment to gain crucial information on the complex biology of health and disease in plants, animals and humans. The center, located on the second floor of the Christopher S. Bond Life Sciences Center on the MU campus, is one of a few in the country that encourages interdisciplinary research in metabolomics.

Anthrax: villain or misunderstood?

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Stewart holds a different colony of anthrax in his lab. Stewart’s work with anthrax and other similar organisms focuses on understanding the tough protein shell of the bacteria’s spores that enable the pathogen to survive in soil for extended periods of time, even hundreds of years. | photo by Phillip Sitter, Bond LSC

By Phillip Sitter | MU Bond Life Sciences Center

For a tiny spore, anthrax holds a lot of danger and promise.

If you found yourself wondering about more than its safety in the lab, we have a answers to a few persistent questions.

What makes anthrax dangerous, and how does it spread? How common are infections of it in nature? If we have antibiotics that already treat it, beyond finding new and better ones why study the organism?

Bovine slayer and bio-weapon

Anthrax bacteria are highly resilient organisms. Like only a few other bacteria in nature, they produce spores with protein-shelled casings that lay dormant in soil for long periods of time, waiting to be taken in by grazing animals like cattle and sheep.

Once they enter the nutrient-rich environment of an animal’s bloodstream — exactly how the bacteria gets there after entering an animal’s mouth is unknown — spores germinate inside the white blood cells that absorb them. As anthrax reproduces rapidly inside its host, it releases toxins that quickly kill the infected animal. That sometimes happens in just a matter of hours according to farmers’ accounts, said George Stewart, Bond Life Sciences Center scientist, medical bacteriologist, McKee Professor of Microbial Pathogenesis and chair of Veterinary Pathobiology at MU.

When infected animals die the bacteria are exposed to oxygen in air that penetrates the decomposing body and new spores escape as the dead host decays. The newly-produced spores are deposited back into the soil, where they wait in a state of suspended animation for as long as it takes to be ingested by another grazing animal, sometimes decades to a hundred years.

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“Most of these plates are anthrax, but they’re all non-virulent,” Stewart says of the various bacterial colonies on the counter in his lab. Non-virulent strains are safe to handle with the precautions of a BSL-2 lab: gloves, a lab coat and eye protection. The Bond LSC does not have a BSL-3 or higher facility to study more dangerous pathogens like virulent strains of anthrax. That work is done at the Laboratory for Infectious Disease Research, or LIDR. | photo by Phillip Sitter, Bond LSC

Sporadic, natural outbreaks of anthrax can happen almost anywhere in the world except Antarctica, as the spores have been found to exist worldwide, Stewart said. In the United States, outbreaks in cattle and bison usually happen in the Plains and West in states like Colorado and Wyoming — anywhere that cattle or sheep have been raised or their wildlife equivalents graze, lending to the descriptor from Stewart of “anthrax belt” for the states stretching from Texas to the Dakotas.

During the Cold War, the U.S. and the Soviet Union, among others, were attracted to anthrax for their respective biological weapons programs because of the hardiness of the organism and high lethality rates of untreated gastrointestinal and, especially, pulmonary anthrax infections in humans. Today, Americans’ are probably most familiar with anthrax from the mailing attacks of 2001, when letters containing weaponized anthrax spores were delivered to the offices of media outlets and politicians, infecting 22 people and killing five. 

Hero in a half-life shell?

Despite their grim reputation, anthrax spores hold a lot of potential for Stewart.

The outermost layer of the protein-shell structure of a spore holds particular interest — how it’s made, what proteins it’s composed of and the function of those proteins. Studying it could not only help find future anthrax vaccines and therapies, but also be used for other applications.

Scientists have coated spores of a close biological relative of anthrax, Bacillus thuringiensis, with plant growth-promoting and anti-insect enzymes and other proteins to treat crops. Its durable structure in the form of the spore’s protein shell attach to these enzymes and remain longer in the environment, making them more effective, Stewart said.

This long biological half-life even presents potential for bio-remediation work — using natural organisms to cleanse the environment of toxins and pollutants. In the case of B. thuringiensis, this might include cleaning up soil from the herbicide atrazine and the notorious pollutant dioxin, a by-product of various industrial processes including incineration, smelting and the production of paper pulp and some herbicides and pesticides.

According to collective findings of the National Institutes of Health and Environmental Protection Agency and others, atrazine is probably not a human carcinogen but can cause genetic damage in animals and is still acutely toxic to people at high enough levels. According to the World Health Organization (WHO), dioxin causes cancer and other ill human ailments.

Pollutants that contaminate soil can eventually leech into groundwater and also enter the food supply through grazing animals. That makes organisms adapted to living in soil like B. thuringiensis perfect candidates as potential carriers of agents used to clean up soil pollutants like atrazine and dioxin.

However, Stewart said that there is too much public stigma to use anthrax for similar applications, “which is too bad because Bacillus anthracis actually works a little better in these applications.”

Rethinking the anthrax image 

So is anthrax a dastardly bio-villain or a misunderstood hero?

The truth is neither. Anthrax bacterium is just another living thing.

As a predator of other living things, needing to feed to survive and reproduce, it goes about its life cycle without any conscious agenda. It has no malice, and unlike a wolf, shark or hawk it doesn’t have a brain so it doesn’t even have instinct, only genetic code to mindlessly live by.

How we interact with anthrax is largely dependent upon us humans.

We have the vaccines to prevent it and antibiotics to treat it if it makes us sick. After that, we can harness and modify anthrax’s natural power for ill as a weapon, or maybe to do some good in the environment. So long as we have the technology to study and manipulate organisms like anthrax, the potential for both scenarios will always be there.

Meanwhile, at MU Stewart will continue to study anthrax, searching for its secrets in order to better understand it, to better serve the rest of us.

The co-evolutionary battle between butterflies and broccoli

Next time you squirt mustard on a sandwich on enjoy wasabi with your sushi, you can thank a battle between broccoli and butterflies. Just ask Bond LSC biologist Chris Pires, our latest scientist in our Decoding Science audio series that runs on KBIA, 91.3 FM.

Pires has studied the process of co-evolution between plants in the order Brassica — including broccoli, caulifower and kale — and insects in the cabbage butterfly family to prove that this back and forth helped make both into what they are today.

Under the hood

The safety behind studying deadly disease
By Phillip Sitter | MU Bond Life Sciences Center

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George Stewart, McKee Professor of Microbial Pathogenesis and Chair of Veterinary Pathobiology holds up a colony of Bacillus anthracis in his lab. The strain of anthrax he holds is non-virulent, and is therefore safe to handle under BSL-2 precautions as opposed to BSL-3 for virulent strains that cause disease in humans. | photo by Phillip Sitter, Bond LSC

You’ve seen it before in the movies.

Sweaty scientists put on their full-body, spacesuit-like get-ups to stave off a potentially extinction-level outbreak and at least one scientist invariably gets infected with the deadly agent of disease.

While popular culture propagates this sense of peril, in reality bio-containment labs are designed with safety in mind.

“People tend to think bio-containment facilities are dangerous, mostly from movies I think, but the history is actually spectacular,” said George Stewart, a medical bacteriologist, a Bond Life Sciences Center scientist, McKee Professor of Microbial Pathogenesis and Chair of Veterinary Pathobiology.

For Stewart — whose lab works on the basic science behind anthrax — no one is “under the gun because of big outbreaks, not with the pressure you see in movies.”

But one type of pressure is an important part of bio-containment lab safety. Air pressure differences maintain certain labs at lower pressure compared to the rooms and hallways around them, ensuring that air will only flow in toward a lab and not out, keeping any airborne pathogens trapped inside.

“They know if everything is done properly, it’s perfectly safe for them and even safer for everyone else [outside a lab],” Stewart said of the safety features, procedures and systems of bio-containment lab safety in place at facilities like those at the Bond LSC and elsewhere at MU.

Stewart said he is vaccinated against anthrax. “Whether I have protective immunity or not, I don’t know.”

 

“Almost like you were working underwater”

The powerful capabilities of anthrax and other lethal pathogens call for particular safety precautions for scientists.

Stewart looks like he’s straight out of the movie Contagion when donning the full-body suit for his more dangerous research in a Bio-Safety Level (BSL) 3 facility at MU’s Laboratory for Infectious Disease Research (LIDR). In the trees on the eastern fringes of campus, the specialized building is where he and other researchers study diseases animals can transmit to humans, including plague, Brucella, tularemia and Q fever, and mosquito-borne diseases like dengue, chikungunya and now Zika virus. The safety protocols and systems at a BSL-3 lab like the LIDR facility Stewart described reflect the likely transmission by aerosols of the human pathogens inside.

After passing through security access to the building and the labs inside, Stewart enters an ante room off of a hallway. The air pressure in this room and the lab beyond it is such that air will only flow in toward the lab, and not out and away.

Anything that goes into the lab only leaves if it is autoclaved, disinfected in a steel machine using pressurized steam that “essentially kills everything, even heat-resistant spores,” so that means Stewart changes clothes, removes his watch, phone and any other personal items.

Next come layered scrubs and a water-proof Tyvek suit with booties and a hood that cover everything but his hands and face. Two layers of gloves take care of his hands, but shielding his face is a bit more technical.

A plastic face cover with a Tyvek hood shrouds over Stewart’s shoulders. Inside, a pump fills the hood with positively-pressured filtered air – this has the inverse effect of the negative pressure of the rooms and keeps air flowing out away from his face and not toward it.

Everything inside the lab and the building is about redundancies like that. A final safety measure is that all work on pathogens take place in bio-safety hoods – HEPA-filtered cabinets.

Stewart said it can be difficult to hear with the air filter systems blowing, so every move by researchers is calculated and announced. Colleagues take their time in handing off equipment to one another, so as to avoid torn gloves.

It’s “almost like you were working underwater as two divers,” Stewart said about working in the BSL-3 lab with a colleague.

“Everything is orchestrated in a very intentional way.”
Only dangerous when dry

Anthrax isn’t always lethal, so the scene is quite different inside a BSL-2 lab at Bond LSC where Stewart studies non-virulent strains.

BSL-2 labs study infectious agents that can cause disease in humans, but are usually treatable. Researchers only need lab coats, gloves and eye protection in these labs and all waste must be autoclaved. Here anthrax and other colonies of organisms are stacked in covered Petri dishes and handled without any Tyvek or air pumps.

The Anthrax bacterium researched here is missing a specific plasmid, a DNA molecule essential for virulence that protects the anthrax bacteria from white blood cells that attack them.

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Stewart holds a colony of anthrax and says that it is impossible to see a visually recognizable colony like this naturally in soil. | photo by Phillip Sitter, Bond LSC

On top of that, all samples in this lab are wet, and anthrax spores are only dangerous as aerosols when dry. Before 2001, Stewart said virulent strains of anthrax were only labeled BSL-2 agents for this reason.

The anthrax letter attacks that year not only changed some of the organism’s lab classifications, but also interest in it. Prior to 2001, Stewart said there was not a lot of funding available for anthrax-focused researchers, a small and tight-knit community. Even though the attacks did spur an increased investment of government money into the field at the time for defense against anthrax as a bio-weapon agent, almost 15 years later Stewart said that funding is more or less back at pre-2001 levels, “perhaps marginally better.”

There are now only a handful of anthrax-dedicated labs in the U.S., Stewart said, trying to name them off as he counted his fingers. The Bond LSC has not had any lab higher than a BSL-2 plus for years now, not since the BSL-3 research moved to LIDR, Stewart said.

Several local residents called when LIDR was under construction and asked questions and voiced concerns about the facility and the work to be done there, Stewart recalled. However, Stewart said he and his colleagues gave the callers honest answers, and he has not heard of any pushback since.

Stewart sees bio-containment labs as positive technological achievements in the study of disease – without them, many advances in treatment would never have been possible. In terms of the work done at facilities at MU and in the Bond LSC, Stewart said “we have the facilities, we have the equipment, we have the training,” to ensure the safety of researchers inside the labs, and even more so everyone else on the outside.

Anthrax is not contagious and responds well to antibiotics, despite concerns in the scientific community Stewart shared that there is a possibility antibiotic resistance could be intentionally engineered into anthrax.

Stewart could only think of a couple of cases when lab workers got infected with the organism through mishaps, and those were at USAMRIID – the United States Army Medical Research Institute for Infectious Disease at Fort Detrick, Maryland – when anthrax was produced there in very large quantities for research of it as a bio-weapon during the Cold War.

When you spend a lot of your time working with potentially lethal pathogens though, what do you tell your doctor when you come in with flu-like symptoms? Stewart said that not only does he and any of his colleagues disclose to their doctor the organisms that they work with, but doctors at MU already know exactly what organisms are being researched inside the LIDR labs. As a precautionary measure for their own well-being in case accidental infection did occur in a lab after all, Stewart or another colleague working with anthrax who turned up sick would receive antibiotics just to be safe – “there are standard operating procedures for everything.”

He does not want to make light of the dangerous organisms he works with, but inside the BSL-3 facility at LIDR, Stewart said that breathing in HEPA-filtered air all day there does do wonders for his hay fever.

Stewart couldn’t help but share a chuckle with that one. Laughter might be the most un-containable thing in nature.

One step closer from mice to men

Gene therapy treating the neurodegenerative disease, SMARD1, shows promising results in mice studies.

Shababi uses an instrument to measure grip strength in the forelimbs of mice. Healthy mice are able to cling to the rack with a stronger grip than SMARD1 mice. | photo by Jennifer Lu, Bond LSC .

Shababi uses an instrument to measure grip strength in the forelimbs of mice. Healthy mice are able to cling on with a stronger grip than SMARD1 mice. | photo by Jennifer Lu, Bond LSC

Monir Shababi was confident her experiments treating a rare genetic disease would yield positive results before she even ran them.

Scientists had success with a similar degenerative neuromuscular disease, so she had every expectation their strategy would work just as well in her mice.

Monir Shababi, assistant research professor in the Department of Veterinary Pathobiology, studies SMARD1 in mice. | photo courtesy of the Department of Veterinary Pathobiology

Monir Shababi, an assistant research professor in the Department of Veterinary Pathobiology, studies SMARD1 in mice. | photo courtesy of the Department of Veterinary Pathobiology

“I was expecting to get the same results,” said Shababi, an assistant research profession in Christian Lorson’s lab at the University of Missouri Bond Life Sciences Center. Shababi studies spinal muscular atrophy with respiratory disease type 1, or SMARD1.

The treatment worked, but not without a few surprises.

Her findings, published in Molecular Therapy, a journal by Nature Publishing Group, are one of the first to show how gene therapy can effectively reverse SMARD1 symptoms in mice.

In patients, SMARD1 is considered such a rare genetic disorder by the U.S. National Library of Medicine that no one knows how frequently the disease occurs. It’s only when babies develop the first symptom—trouble breathing–that pediatricians screen for SMARD1.

Shortly after diagnosis, muscle weakness appears in the hands and feet before spreading inwards to the rest of the body. The average life expectancy for a child diagnosed with SMARD1 is 13 months. There is currently no effective treatment.

Since the neuromuscular disease is caused by a recessive gene, SMARD1 comes as a shock to the parents, who are carriers but do not show signs of the illness, Shababi said. This genetic defect prevents cells from making a particular protein that scientists suspect is vital to replication and protein production.

The hereditary nature of the disease has a silver lining, though. Because SMARD1 is a caused by a single pair of faulty genes and not multiple ones, it is a prime candidate for gene therapy that could restore the missing protein and reverse the disease.

To do that, Shababi set up a dose-response study using a tiny virus to carry the genetic instructions for making the missing protein. She injected newborn mice with a low dose of the virus, a high dose, or a placebo with no virus at all.

Injecting at different doses allowed her to ask which dose worked better, Shababi said.

According to the previous research, a higher dose should have resulted in a more effective treatment.

“So I thought a higher dose was going to work better,” Shababi said.

Instead, the high dose had a toxic effect. Mice given more of the virus died sooner than untreated mice. Meanwhile, mice given a low dose of the gene therapy lived longest. They regained muscle function and strength in both the forearms and the hind limbs and became more active.

In fact, some of them survived long enough to mate and produce offspring.

Initially, Shababi housed her SMARD1 mice in the same cage as their mothers so that the moms could intervene if the sick pups become too feeble to feed themselves. When the male pups became well, their moms became pregnant.

“That was another surprise,” Shababi said. “That was when I knew I had to separate them.”

Shababi marks a pup, only a few days old, with permanent marker so she can identify each mouse in her study. | photo by Jennifer Lu, Bond LSC .

Shababi marks a pup, only a few days old, with permanent marker so each mouse in her study can be identified. | photo by Jennifer Lu, Bond LSC .

In another twist, Shababi discovered that the route of injection also mattered.

To get the treatment across the blood-brain barrier and to the spinal cord, Shababi used a special type of injection that passes through the skull and the ventricles of the brain, and into the spine.

This was no easy task.

The newborn mice were no larger than a gummy bear. To perform the delicate work, Shababi — who has written a chapter in a gene delivery textbook about this procedure — had to craft special needles with tips fine enough for this injection. She added food coloring to the injection solution so she could tell when it had reached its intended destination.

“After half an hour, you will see it in the spinal cord,” Shababi said. “The blue line in the spine: that’s how you can monitor the accuracy of the injection.”

Unfortunately, repeated injections in the mice caused hydrocephaly, or swelling in the brain.

“They get a dome-shaped head,” Shababi explained.

The swelling happened in all three treatment groups, but most frequently in the group that received a high dose of viral gene therapy. This reinforced the finding that while a low dose was beneficial, a high dose was even more harmful than no treatment at all. It’s unclear why.

Christian Lorson is a professor of veterinary pathobiology at the Bond LSC. His research focuses on spinal muscular atrophy and more recently, SMARD1. | photo by Hannah Baldwin, Bond LSC .

Christian Lorson is a professor of veterinary pathobiology at the Bond LSC. His research focuses on spinal muscular atrophy and more recently, SMARD1. | photo by Hannah Baldwin, Bond LSC .

The Lorson lab plans to continue studying SMARD1 and this treatment, in particular, how changing the delivery routes for gene therapy can improve outcomes in treating SMARD1.

“It’s not as simple as replacing the gene,” Lorson said. “It comes down to the delivery.”

Injections in the brains of mice are meant to mimic spinal cord injections in humans, but intravenous delivery could be another option. However, intravenous injections, which travel through the blood stream and to the entire body, might cause off-target effects that could interfere with the effectiveness of the treatment.

Once researchers better understand how to optimize dosing and delivery on the cellular and organismal level, the therapy can move closer to clinical trials, Lorson said.

Even though gene therapy for SMARD1 is still in its early stages, he said he was optimistic that developing treatments for rare genetic diseases is no longer the impossible task it seemed even ten years ago.

Spinal muscular atrophy (SMA) is a prime example of a recent success, Lorson pointed out. In the last six years, gene therapy for that disease has moved from the research lab to Phase I clinical trials.

“While it feels like a long time for any patient and their families,” Lorson reassured, “things are moving at a breakneck pace.”

 

The study, “Rescue of a Mouse Model of Spinal Muscular Atrophy With Respiratory Distress Type 1 by AAV9-IGHMBP2 Is Dose Dependent,” was published in Molecular Therapy, a journal published by Nature Publishing Group. This work was supported by a MU Research Board Grant (C.L.L.); MU College of Veterinary Medicine Faculty Research Grant (M.S.); the SMA Foundation (C.P.K.); National Institute of Health/National Institute of Neurological Disorders and Stroke grants; and the Missouri Spinal Cord Injury Research Program (M.L.G.).