New research has found why B-cells in rheumatoid arthritis produce protein antibodies that attack the healthy proteins of the body. B-cells are also known as white blood cells. The research was published in the Journal 'Arthritis and Rheumatology'.
"To the best of our knowledge, this is the first study to conduct whole transcriptome profiling of antigen-specific B cells in any human autoimmune disorder," said Varadarajan, the researcher. He further added, "We anticipate that these data will serve as a foundational data set for investigating multiple hypotheses on the roles of B cells in RA and other autoimmune disorders, and will enable drug discovery."
B-cells activate to produce an antibody as soon as a new pathogen is encountered in the body. Every person has between 10-100 million unique B cells, each capable of making its own antibody. While antibodies are the natural way the body fights infections, in the autoimmune RA, these antibodies attack the body's own proteins and are thus called autoantibodies.
Less than 1000 B-cells are autoreactive. So, to find them, the researchers designed a method to identify and isolate the population. They then used RNA sequencing to study all the RNA being produced by each cell. "We wanted to understand if there's anything special about this class of white blood cells, the autoreactive B cells that make autoantibodies, that would make them fight against healthy proteins," said Varadarajan.
A number of pathways associated with inflammation and protein modification, known to be amplified in rheumatoid arthritis, were found. The team found two specific differences in the B cells of RA patients - the inclusion of the protein interleukin 15 receptor subunit alpha (IL-15Ra) and a high amount of the amphiregulin molecule. "We think that protein allows them to become bad actors. People have been targeting this pathway for quite some time. This now sheds new light on these bad guys in the progression of this disease and how to target it," said Varadrajan.
(With inputs from agencies.)