Researchers say these cells can travel to the brain and help diminish inflammation.
Plasma cells, once considered the arsonists of multiple sclerosis (MS), are actually showing up to fight against the disease.
“It’s astounding,” Bruce Bebo, PhD, executive vice president of research at the National Multiple Sclerosis Society, told Healthline. “This observation, that plasma cells migrate from gut to brain and have a role in regulating a mouse model of MS, is incredibly unique and different. I’ve never heard of an observation like this before.”
Researchers say that microbes in the gut can trigger a change in plasma, which is originally produced in bone marrow as B cells.
“We found that not all plasma cells are bad. In autoimmune disease, some quiet the inflammation,” Jennifer L. Gommerman, PhD, a study author and professor and associate chair of graduate studies in the department of immunology at the University of Toronto, told Healthline.
“We also found that plasma cells in the gut make an immunoglobulin called IgA and have capacity to make other products to end inflammation. And, they have the ability to migrate to other parts of body,” she added.
“[The research] gives us ideas of potentially treating the disease,” said Gommerman. “Plasma cells go to the brain. The trouble with anti-inflammatories is getting drugs into the brain. This might be a solution.”
Sergio E. Baranzini, PhD, a professor in the department of neurology at University of California, San Francisco, noted that Gommerman studied mice, but human studies have shown similar results.
“[We’re] focusing on a role of gut bacteria and MS. We are mapping all the gut bacteria that we think are linked to MS, or at least more prevalent or less prevalent,” Baranzini told Healthline.
Gommerman and Baranzini met 1 1/2 years ago at a conference.
After seeing the similarities in their research, they decided to collaborate.
“We observed that during a relapse the quantities of IgA diminished in the gut,” Baranzini explained. “And, we found that during a relapse there was an increase of IgA in cerebral spinal fluid.”
“Then we found that once they go to the brain, they are helping by producing interleukin 10 (IL-10), which dampens inflammation,” he said.
“Typically, antibodies are directed against something specific, for example the flu,” he noted. “We still don’t know what the specifics of the IgA is, so we are now working on identifying this specificity.”
Gommerman said their experiments were done genetically.
“But, can we do it pharmacologically and make this concept into a drug?” she said.
“We need to look closer at the gut to see how we encourage the presence of these cells in the brain by having the right microbes in the gut,” she said. “It could potentially direct an immune response that is beneficial for MS patients.”
“The gut is a major immune organ, and it is known that there are important interactions between gut immune function, gut microbes, and MS,” explained Dr. Barbara Giesser, professor of clinical neurology at the David Geffen School of Medicine at the University of California, Los Angeles (UCLA) and clinical director of the UCLA MS program.
“This study, by reporting that gut immune cells can travel to the brain and reduce inflammation, elucidates what appears to be a key mechanism by which the gut immune cells and the gut microbiome can influence immune function in MS, and may be an avenue for future therapeutic intervention,” Giesser told Healthline.
The study was partially funded by the National Multiple Sclerosis Society as part of a larger portfolio of research between microbiota and the health of the gut on the brain.
Research has found that gut microbiota differed between healthy people and those living with MS. The differences have not been the same across the board.
Bebo said there is “no causal connection, just an association” between gut health and MS.
“We want to understand how these cells can be promoted by a healthy microbiome and what this looks like,” Bebo said. “There is nothing actionable yet. We don’t know to what degree the cells are controlling the immune response leading to the damage from MS.”
“The paper implies that they play a role,” he said. “We need to better understand our diet and how manipulating microbiota in [the] gut can positively affect our health. This research triggers unanswered questions and opens up a whole new area of investigation.”
“There is growing evidence of gut bacteria and its effects on the brain,” Bebo added. “We are unraveling the connection, and this is a big step in enhancing our knowledge.”