Bacteria in the gut stimulate the formation of immune cells

A new study reveals that some types of intestinal bacteria stimulate the formation of immune cells, which could be a prerequisite for new treatments for inflammatory bowel disease and other diseases.

Research by scientists at NYU Langone Medical Center was published October 16 in the journal Cell Host and Microbe. This finding shows that some types of bacteria in the stomach, and in the stomach, have an impact on our health.

Dr. Yasmine Belkaid, who directs the immunology research group in the parasitic disease laboratory at the National Institutes of Health, said: 'More and more evidence of the important effects of microbial populations in the gut for human health. If some bacteria can stimulate a specific immune response, it may be a way to regulate the immune system. This is the first study to report on a defined group of bacteria that stimulate some immune cells. '

The study was done at the lab of Dan Littmna, professor, doctor, doctor of Molecular Immunology at NYU Medical School, and a Howard Hughes Medical Institute researcher. Littman said: 'The important thing is the type of bacterial population, not the number of bacterial populations'.

The study found that cytophaga-flavobacter-bacteroidetes (CFB) bacteria were involved in the formation of Th17 cells in mice. In both humans and mice, most bacteria found in the stomach belong to the CFB system or another system called Firmicutes. These bacteria play many roles, such as helping digestion and resistance to disease by overwhelming harmful bacteria.

Intestinal inflammation (IBD) affects 700,000 people a year and is one of the most common gastrointestinal diseases in the United States. Treatment with antibiotics is not effective. However, identifying the types of bacteria that affect the balance of inflammatory cells is the start of more sophisticated treatments.

A new study reveals that some types of intestinal bacteria stimulate the formation of immune cells(Photo: etlutheran.org)

Immune Yin and Yang

A healthy immune system ensures a balance between two opposing 'forces' that are closely linked, sometimes called immune adaptation to yin and yang.The inflammatory (positive) cells dominate when the body needs protection, and the control cells (negative) calm the immune system when the body does not need to be protected.

When this balance is broken, and the positive cells overwhelm, the infection will appear. In recent years, some autoimmune disorders have been the result of too many inflammatory cells, including psoriasis, intestinal inflammation, and sclerosis. Dr. Littman said: 'The number of inflammatory diseases in the presence of 17 helper T cells (Th17) is known to increase rapidly'.

For this reason, Dr. Littman investigated the processes that stimulate the formation of these types of cells. Recently, his team discovered a promising therapeutic goal that could help improve. diseases related to excess cells of the 17th cell.

In the new study, Dr. Littman's team observed that a newborn mouse was isolated from bacteria and never formed these cells. Normally, there are no bacteria or Th17 cells in the intestines of newborn babies. These cells form when they begin to eat and become infected with bacteria.These observations show the presence of intestinal bacteria in relation to the formation of Th17 cells.

To determine whether the bacteria were responsible for the formation of Th17 cells, the team used normal mice to use other drugs to kill some of the bacteria in the gut. Some antibiotics also remove Th17 cells, indicating a link between bacteria and inflammatory cell formation.

Littman's team later discovered a group of mice infected with intestinal bacteria but did not have Th17 cells. These rats infected with different types of bacteria compared to other herds. Dr. Ivaylo Ivanov, an author of research work at Dr. Littman's lab, explained: 'This is similar to the fact that people from different countries are infected with different types of bacteria in mice and mice. From different flocks, there are different types of bacteria. A herd can be infected with bacteria that is associated with Th17 cells while this relationship does not exist in another herd. '

By comparing intestinal bacteria in mice, the team found that cytophaga-flavobacter-bacteroidetes (CFB) bacteria are involved in Th17 cell formation. The team is currently trying to identify specific bacteria that stimulate inflammatory immune cells in mice.They will use the information found to determine the specific type of bacteria in the human gut that creates the excess of this type of cell.

Dr. Littman is also interested in the effect of the signal that bacteria emit on the innate immune system. The innate immune system responds to direct risks from strange pathogens and produces stimulants that normal T cells grow into Th17 cells. Control of bacteria can be a method of shifting the balance between inflammatory cells and control cells