Australian scientists have discovered that when a gene called ‘TLR7’ is over-activated, it causes lupus, a chronic autoimmune disease. This genetic mutation was detected in a young Spanish patient.
- Lupus occurs in women in 90% of cases and most often begins between puberty and menopause with a peak frequency between 30 and 39 years.
- The “TLR7” gene is present on the X chromosome. Women have two X chromosomes and thus two copies of the “TLR7” gene.
- “This means that women with an overactive TLR7 gene may have two working copies, which may double the risk,” the researchers said.
41 people out of 100,000. This is the number of French people with systemic lupus erythematosus (SLE). In this multi-organ disease, the immune system mistakenly attacks healthy cells and tissues in the body in the absence of antigens. For the time being, the causes of this immune dysregulation remain unknown. However, certain elements favoring this chronic autoimmune disease have been identified. According to health insuranceseveral genes are involved in the onset of lupus.
Recently, researchers at the Australian National University in Canberra identified a particular gene that may be responsible for causing this condition. “Although circumstantial evidence supports that increased Toll-like receptor 7 (TLR7) signaling is a mechanism of systemic autoimmune disease, there is no evidence for the existence of genetic variants of TLR7 causing lupus”they wrote in work published in the journal Nature April 27.
A genetic cause of lupus discovered thanks to a little girl
Scientists discovered that this gene, named “TLR7”, could be involved in the occurrence of this autoimmune disease thanks to a young Spanish girl, Gabriela, who learned at the age of seven that she suffered from lupus . In this patient, a mutation of the “TLR7” gene was identified. As a reminder, this gene helps the immune system to protect itself against viral infections, but in its mutated form, it can become aggressive and cause the immune system to attack healthy cells.
Using a gene-editing tool, the team introduced the human-derived mutation into mice to study whether the pathology developed in rodents. “Mice carrying the mutant TLR7 gene developed a condition that mimics severe autoimmune disease in human patients, providing evidence that the TLR7 mutation causes lupus,” said Grant J. Brown, author of the research, in a statement.
“The possibility of developing new drugs targeting TLR7”
“This is the first time that scientists have shown that a genetic variation in the TLR7 gene is a driver of autoimmune disease,” said Vicki Athanasopoulos, co-author of the work. The authors added that this finding raises “the possibility of developing new drugs targeting TLR7, which could revolutionize lupus treatments.”They are currently working with pharmaceutical companies to develop new treatments or modify existing drugs to target the “TLR7” gene.
