Bonus episode 58. Under the microscope with Dr. Leona Gilbert

In this podcast we catch up with Dr. Leona Gilbert to take an inside look at the Lyme bacteria, Borrelia, and find out how it interacts with our cells and how it can evade our immune system. Dr. Gilbert has a doctorate in biotechnology with an extensive background in bio-innovation and bio-business. We’ll also find out more about her research and the impact it is having on how we understand Lyme disease and associated infections. Dr. Gilbert is originally from Canada and is now based in Finland. 

When immune cells meet Borrelia

Dr. Gilbert describes the basic process that occurs when Borrelia is encountered in the body by an immune cell called a macrophage. She explains that during this process, the macrophage displays proteins on the surface of the macrophage in order for the immune system to be able to recognize Borrelia. She highlights some of the unique characteristics of Borrelia which include its long length, very thin “hair like” width and its corkscrew shape. Macrophages in turn are required to use specific mechanisms in order to process this large and irregular pathogen. They have arm-like protrusions that envelop Borellia, which then curl up before being ingested into the cell.

“Borrelia is a corkscrew-like structure, so it’s kind of coiling and it’s really 20 micrometers in length and 200 nanometers width, so it’s very thin, and pleomorphic means it can change its shape based on its environment…when Borrelia is faced with an adverse environment…it recognises the environment is stressful for them, so they tend to protrude its outer membrane and make these little blebs, and the blebs actually ball out…and make these round bodies.”

Dr. Leona Gilbert

Borrelia is a shapeshifter

Borrelia can be described as “pleomorphic”. Because of it’s long, thin, corkscrew structure, it can change its shape depending on its environment. For example, if Borrelia senses an adverse environment such as change in pH or nutrients, it protrudes its outer membrane to create “blebs” which progress into “round bodies”. Round bodies are circular and contain coiled up genetic material of Borrelia. In the past, it was thought that these round bodies were cell wall deficient, but research is showing that they actually do have a cell wall. 

“We also have noticed in vitro as well as in vivo studies of ours and others, that Borrelia can form biofilm structures…they like to clump together…it’s been speculated that the biofilm is a really resistant form to protect the bacteria against antibiotics and so forth, but in that biofilm it’s also having different pleomorphic forms…the spirochete (parent) form, the round body form…spirochetes with these blebs, you will see all of that in the biofilm-like structures.”

Dr. Leona Gilbert

Sheltering in biofilms

Dr. Gilbert explains that in human, animal and laboratory studies, Borrelia can be found in biofilm structures in which Borrelia group together. The bacteria will recruit elements in their environment, such as proteins in the blood, to create an extracellular matrix for the biofilm to attach itself to. Tissue testing has shown that these biofilms have been found in joints as well as brain tissue. She notes that the different forms of Borrelia can be found in the biofilm, including the parent form, the blebs and the round bodies. Through something called quorum sensing, the bacteria share genetic material which support persistent forms of Borrelia. Newer research indicates that these biofilms may include other microbes as well.

“(Borrelia) will actually recruit other kinds of proteins there to create this extracellular matrix so that the biofilm can attach itself…and start building up, really a solid structure. We have seen this in the joints of people and in the brains of…autopsy samples.”

Dr. Leona Gilbert

Under the microscope

In order to better understand Borrelia, transmission electron microscopy is used. Electrons go through the cellular structure so that the interior and exterior structures can be visualized. Through a process called immuno-labeling, antibodies for specific structures in Borrelia such as its DNA, outer surface proteins, or p41 of the flagella are employed to be able to “label” each of these structures in order to better understand them. Immunolabeling can also help scientists understand how Borrelia and its components interact with immune cells such as macrophages.

Focus on skin and joint cells

To better understand how Borrelia behaves in humans, Dr. Gilbert’s team used skin and joint cells in their research. They infected these cells at different time intervals to see if Borrelia can survive inside the cell. Their research showed that Borrelia were indeed able to survive inside the skin and joint cells. Unlike some other pathogens that kill host cells, Borrelia appears to “hide out” within the cell in order to protect itself. They also found that Borrelia exists in different forms in each of the cell types. In the joint cells, which are more acidic, Borrelia was more likely to morph into round bodies than in the skin cells.

“These persistent reserves, these are these niches of where Borrelia wants to hide out…lymph nodes…they really can affect the overall antibody production pathway that’s occurring in the host…we also know the niches like the knee, they eyes, the brain…(the vagus nerve) could be a niche as well.”

Dr. Leona Gilbert

Exploring cell death and persistence

Dr. Gilbert explains some of the science behind cell death. Apoptosis is the regular or “programmed” cell death that occurs to enable healthy regeneration of new cells. In contrast, necrosis, or unprogrammed cell death occurs during tissue damage. Different types of cell death result in different markers being detected in the tissue. Through these research techniques, the differences in cell death between various immune cells can be explored. Dr. Gilbert’s team also found that the skin and joint cell lines they were testing were surviving, and explains that this discovery will create new avenues of research.

Mechanisms of persistence

Various places in the body can become reservoirs for Borrelia bacteria, including lymph nodes. Dr. Gilbert notes that their presence there seems to also “downregulate” immune processes in the body. Other “niches” for Borrelia are the knees, the eyes, the brain and possibly the vagus nerve. Borrelia may evade the immune system by hiding out in these areas. Why do some patients have symptoms after treatment for Lyme disease? Dr. Gilbert describes some of the potential reasons that some patients have symptoms after treatment for Lyme disease. These include persistent infection, persistent antigens, autoimmune processes and immune dysfunction. 

“What is the mechanism behind post treatment Lyme disease syndrome, or chronic Lyme…is there a persistent infection, or persistent antigens, or is it an autoimmune occurrence, is it immune dysfunction? So there is evidence to suggest that these persistent kind of niches do exist not only in animal studies, non-human primate studies and also in human studies.”

Dr. Leona Gilbert

Extracellular vesicles: creating a diversion

Pathogens such as Borrelia can pump out structures called extracellular vesicles, or EV’s, which contain components of the pathogen inside them. Because the immune system recognizes components inside the EV’s, it may seek out the EV rather than the actual pathogen. Dr. Gilbert explains that while the immune system is distracted by these “decoys”, Borrelia bacteria can invade tissues in the body. She notes that EV’s are also linked to autoimmune diseases and cognitive changes.

A call for more research

Dr. Gilbert explains that she is constantly looking to the patient population to guide her research. As many patients remain symptomatic after treatment with antibiotics, she started to look at the use of phytochemicals or herbal supplements. She found that although there’s good anecdotal evidence to demonstrate the success of these treatments, there is a lack of human research to support their use. She urges clinicians and researchers to fill this gap by developing research studies to better understand the effectiveness of these phytochemicals. Dr. Gilbert shares her own research findings by speaking internationally at Lyme disease and other conferences.

“What is the mechanism behind post treatment Lyme disease syndrome, or chronic Lyme…is there a persistent infection, or persistent antigens, or is it an autoimmune occurrence, is it immune dysfunction? So there is evidence to suggest that these persistent kind of niches do exist not only in animal studies, non-human primate studies and also in human studies.”

Dr. Leona Gilbert

Tezted: testing for Borrelia (and friends)

Tezted is a university spin-off company created to address problems with the two-tier testing system. It also addresses the findings of Dr. Gilbert and other researchers, that patients with Borrelia are often infected with other pathogens such as Bartonella and Babesia. They found that 85% of Lyme patients also have co-infections. Tickplex tests for 15 different microbes, and IgG and IgM with quantification in order to help determine the stage of disease. There is also a test for mycotoxins such as those found in mold. While waiting for approval in Canada, Dr. Gilbert has worked with several labs in Europe, the United States and Mexico. 

“We have this saying that Borrelia likes its friends…we demonstrated that 85% of Lyme patients in that study, and even now in other studies, actually have co-infections.”

Dr. Leona Gilbert

The importance of patient collaboration in research

Dr. Gilbert is passionate about global collaboration to find solutions and highlights the importance of working with patient groups. She works with a group called Lyme Global, which is focussed on collaborating and communicating with people around the world to discuss issues, which she notes are common worldwide. She is also collaborating with Dr. Lambert from Ireland to improve the current database of Lyme disease research. 

Mining data to gain a better understanding

In closing, Dr. Gilbert points to the emerging field of artificial intelligence and machine learning in research. With the help of technology, the data from multiple sources can be mined and clustered to support hypotheses that are otherwise difficult to examine. Thank you Dr. Gilbert for sharing your research with us and with the world!