In 2014, actress and singer Selena Gomez took some time out of the spotlight. While rumours swirled, it turned out that the hiatus was required so she could receive treatment for a disease known as lupus.
Millions of individuals worldwide, mostly women between the ages of 15 to 44, struggle with lupus. It is an autoimmune disease, meaning that the body’s immune system goes into overdrive—attacking and causing extensive damage to healthy tissue.
B cells, named for their production in bone marrow, are one of the body’s most important immune cells; they release specialized proteins (ie, antibodies) that protect the body from invaders such as viruses or bacteria. However, it is believed that they also play a critical role in initiating lupus by producing ‘harmful’ antibodies that tell the immune system to attack healthy cells.
Krembil Senior Scientist Dr. Joan Wither and her team have been using experimental models of lupus to uncover how and why B cells betray the body and incite the immune system to attack healthy cells.
In a recent study, the researchers tracked B cell antibody production using an experimental model in which B cells were forced to express a specific genetic code that induced lupus-like symptoms. The team discovered that this genetic code not only increased the proportion of antibody-producing B cells, but also the levels of antibody production.
The code also increased the proportions of another type of immune cell (T follicular helper cell) that is known to enhance the growth of antibody-producing B cells. As the proportion of these T follicular helper cells increased, the proportion of B cells grew, and likewise, antibody production was augmented. These changes created an environment where the immune system was primed to attack healthy tissues.
“Although several studies have shown that defects in B and T cell populations contribute to antibody production, it still is not clear exactly how this occurs in the context of lupus,” says Dr. Wither. “Our data reveal that changes in the proportion of T follicular helper cells may play a role in this process by enhancing the growth of the types of B cells that end up betraying the body and causing lupus.”
This work was supported by the Canadian Institutes of Health Research, and the Toronto General & Western Hospital Foundation.
Chang NH, Manion KP, Loh C, Pau E, Baglaenko Y, Wither JE. Multiple tolerance defects contribute to the breach of B cell tolerance in New Zealand Black chromosome 1 congenic mice. PLoS One. 2017 Jun 19;12(6):e0179506. doi:10.1371/journal.pone.0179506.