Project 2: Clostridium Perfringens
As detailed in StandUp 2 MS Fundraising Campaign, this first Mind Brain Philanthropic Foundation campaign focuses on two projects. On this page, you’ll learn more about the second project Clostridium Perfringens.
Note: This project was published in the Journal of Clinical Investigation on February 28, 2023. It is titled Epsilon toxin-producing Clostridium perfringens colonize the MS gut and epsilon toxin overcomes immune privilege.
Mind Brain Philanthropic Foundation Founder Regina Schroeder and Treasurer Ian Green are listed in the acknowledgments as they were subjects one and two in the study.
What is Clostridium Perfringens?
Clostridium Perfingens is one of the most common sources of food poisoning. It is also often found in the gut of people with Multiple Sclerosis.
Why Focus on Clostridium Perfringens?
How MS lesions initially form, the factors that drive the opening of the blood-brain barrier, and the factors responsible for initiating demyelination in white matter and in gray matter, are unknown. However, research has shown that people with MS can harbor epsilon toxin-producing strains of Clostridium Perfringens within their gut microbiome.
Epsilon Toxin, the Blood-Brain Barrier, and Myelin
Knowing that the epsilon toxin specifically targets the blood-brain barrier and myelin, the team at Weill Cornell Medical College has considered that it may function in the formation of MS lesions and in cortical demyelination. Using a mouse model of MS (experimental autoimmune encephalomyelitis (EAE)), it found that low doses of epsilon toxin were sufficient to induce multi-focal inflammatory demyelination more closely resembling MS compared to traditional models.
The research team has also shown that epsilon toxin can induce primary cortical demyelination in mice thus providing the only model in which an environmental agent causes an MS-like pathology in the cortex.
Clostridium Perfringens Proposal Objectives
The objectives of this proposal are as follows:
- To determine if epsilon toxin-producing strains of Clostridium perfringens are statistically associated with MS,
- If their presence along with elevated levels of epsilon toxin in the blood is associated with new disease activity, and
- If the transfer of MS patient-derived C. perfringens type B or D strains into the mouse gut microbiome is sufficient to induce experimental autoimmune encephalomyelitis (EAE).
Clostridium Perfringens Hypothesis
The central hypothesis is that people with MS are colonized by C. perfringens types B or D and that epsilon toxin, episodically produced during log-phase growth, enters the bloodstream, and leads to new lesion formation and clinical exacerbations by overcoming CNS immune privilege.
The rationale underlying this proposal is that completion will identify novel pathogen-derived targets useful for preventing MS or limiting disease progression in some patients. The work will also lead to a new animal model of MS based on human-derived pathogenic C. perfringens type B or D strains opening new lines of investigation and testable hypotheses.
Testing the Central Research Hypothesis
The central hypothesis will be tested by pursuing two specific aims.
- In the first aim, determine the frequency of C. perfringens types B or D and blood epsilon toxin levels in MS and healthy controls (HC) in a longitudinal study of three distinct geographical areas: San Juan, Seattle, and New York City. Longitudinally collected samples will be studied for the presence of C. perfringens types B or D in feces and epsilon toxin bound to lymphocytes or present as a free toxin in plasma. Patient-derived C. perfringens type B or D isolates will be sequenced to prove they are not laboratory contaminants and for comparison to environmental strains.
- In the second aim, determine if colonization of the mouse gut microbiome by epsilon toxin-producing strains of C. perfringens isolated from people with MS is sufficient to overcome CNS immune privilege and induce EAE. Then quantify immune infiltrates and CNS injury using high-dimensional flow cytometry, quantitative immunofluorescence, and unbiased histology. The team will genetically delete the epsilon toxin gene from patient isolates to prove epsilon toxin is causative.
What Makes this Clostridium Perfringens Research Stand Out?
The proposed work is innovative because it will establish a biologically plausible infectious trigger relevant for some MS, and experimentally utilizes a novel combination of analytical techniques from microbiology, immunology, computational biology, and molecular genetics.
The proposed research is significant because it will advance the connection between human gut pathogens and CNS autoimmunity through a clinical association of epsilon toxin with MS disease activity in humans, and induction of EAE by transferring human strains to mice harboring myelin autoreactive lymphocytes.
Learn About Project 1
You’re invited to learn more about the first project that the Mind Brain Philanthropic Foundation’s StandUp 2 MS fundraising campaign focuses on. Click on Repurposing Drugs as Remyelination Agents.
Image credit: Clostridium Perfringens from CDC