Globally affecting 4% of the population, autoimmune diseases mistakenly attack healthy cells, tissues and organs in the body.

Researchers from King’s College London’s (KCL) Peter Gorer department of immunobiology have identified key features of autoimmune diseases that are present in the gut at sites where bacteria normally meet the immune system.

The study revealed that autoimmune disease features in the gut are normal components of the immune system that interact with each other alongside bacteria.

Affecting nearly 4% of the world’s population, autoimmune diseases occur when the body’s immune system mistakenly attacks healthy cells, tissues and organs in the body.

Comprising more than 80 different types, the most common autoimmune disorders include type 1 diabetes, multiple sclerosis, rheumatoid arthritis, lupus, Crohn’s disease, psoriasis and scleroderma.

Using a combination of spatial transcriptomics and multiplexed single-ell technologies, researchers pinpointed a B cell subtype in normal intestinal lymphoid tissue in patients living with lupus.

Affecting around five million people globally, lupus is a chronic autoimmune disease that causes inflammation that can lead to permanent tissue damage.

The DN2 B cells were found to interact with dendritic cells in the gut, co-expressing the lupus autoantigens DNASE1L3 and C1q, along with the bacteria.

DN2 B cells, DNASE1L3 and C1q in the gut are said to relate to bacterial recognition, bacterial killing and disposal of bacterial debris, including DNA, which could result in the persistence of bacterial DNA if the system fails, stimulating an autoimmune response.

Jo Spencer, professor of experimental medicine, Peter Gorer department of immunobiology, school of immunobiology and microbial sciences, KCL, commented: “The unexpected outcomes have helped us to understand how the gut immune system interacts with the vast intestinal microbiota.”

Researchers believe that their findings could help to prevent certain autoimmune diseases.

Most recently, researchers from Johns Hopkins Medicine revealed that certain combinations of antiviral proteins are responsible for symptoms and affect treatment outcomes for patients with lupus.

The study published in Cell Reports Medicine could lead to changes in how clinicians treat patients living with the condition.