Can Armadillos Shine Light On Stem Cell Research?

Ryan Argetsinger, 7/23/24

Armadillos are curious creatures because of the fact that they can roll themselves into a ball, have thick skin, but, most importantly, they carry leprosy. This article isn’t particularly meant to discuss armadillos (although, I’m sure we all find them adorable creatures…maybe less so now, knowing they carry a disease that’s tormented countless since biblical times). However, this article will discuss the still mysterious disease, and the applications of their microbial-cell interactions. 

Leprosy (also called Hansen’s Disease) has been around since ancient times and is a strain of infectious bacteria, also known as Mycobacterium leprae. There are references from ancient India, Egypt, and the bible, that have described how leprosy had led to social isolation and ostracization. The disease led to disfigurement, which was the primary cause of social shunning, but the factors that affected most patients were the bacteria’s effect on the eyes, skin, mucous membranes, and are now known to cause nerve damage. Most symptoms can be characterized as so:

• Skin patches and redness

• Loss of pigmentation

• Numbness and tingling

• Painless wounds or burns

• Muscle weakness

• Paralysis

• Vision Loss

• Chronic Ulcers 

• Appendage shortening

The disease poses general risks because it still isn’t understood how it is passed between person to person; it can’t be tested or screened for without a skin biopsy; and it remains dormant for years in patients. Leprosy still exists today, however, the number of infected patients is much lower today at only 208,000, and primarily in Asia and Africa. Furthermore, due to modern medicine and antibiotic development, leprosy is curable and can be treated effectively. In theory this sounds great, but why is leprosy still such a mysterious strain of infectious bacteria?

Research is still discovering how the bacteria is transferred from person to person, but recent findings show something interesting in the infection mechanism. Leprosy targets a range of connective tissue cells and organs, but the discovery most interesting to stem cell research was how the bacteria targeted Schwann cells. Schwann cells are a part of the peripheral nervous system and are responsible for myelination of the peripheral nervous system. When interacting with the Schwann cells, M. leprae reprogrammed the cells into a stem-cell-like state, turning the genes associated with mature Schwann cells into near embryonic or developmental ones. Moresaid, it seemed to trigger Schwann cells’ plasticity, reverting it to a near immature state with the capability to turn into new types of basic cells. Once reprogrammed, these new cells that were converted by the bacterial mechanism are able to move throughout the body, providing the M. leprae with transportation. 

The mechanism that reverted a matured Schwann cell back to a base level stem cell is still being researched, but the capabilities of understanding this process may allow stem cell therapeutics to advance to a whole new level. The current theory shows signs of genetic manipulation, meaning that the M. leprae strain upregulates basic progenitor/stem-like cells (pSLC) of mesoderm or connective tissue like cell traits, while down regulating those of the peripheral nervous system and Schwann cells. 

Although more research is necessary, the potential benefits of researching infectious disease mechanisms has been in practice ever since the creation of the smallpox vaccine and the introduction of penicillin. Utilizing disease strains to improve immune function allows us to better understand how to treat disease, while improving medical treatment for patients through pathologic discoveries. 

References

Reprogramming Adult Schwann Cells to Stem Cell-Like Cells by Leprosy Bacilli Promotes Dissemination of Infection

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4314110/ 

Leprosy bug turns adult cells into stem cells

https://www.nature.com/articles/nature.2013.12239 

Leprosy (Hansen’s Disease) Cleveland Clinic

https://my.clevelandclinic.org/health/diseases/23043-leprosy-hansens-disease