Psoriasis and psoriatic arthritis are forms of autoimmune disease. These types of diseases occur when the immune system attacks healthy cells after wrongly perceiving them as a threat. Although there is no cure for psoriasis, there are treatments that can help manage the condition. Now, researchers from the Australian National University (ANU) report they have uncovered a gene mutation that is responsible for causing psoriasis. The researchers discovered if two copies of the mutated gene (known as IKBKB) are present, patients with psoriasis may go on to develop psoriatic arthritis. Their findings may lead to improved diagnosis and treatment for patients with psoriasis and psoriatic arthritis.
Their new study is published in Nature Communications in an article titled, “IKK2 controls the inflammatory potential of tissue-resident regulatory T cells in a murine gain of function model.”
“Loss-of-function mutations have provided crucial insights into the immunoregulatory actions of Foxp3+ regulatory T cells (Tregs),” the researchers wrote. “By contrast, we know very little about the consequences of defects that amplify aspects of Treg function or differentiation. Here we show that mice heterozygous for an Ikbkb gain-of-function mutation develop psoriasis. Doubling the gene dose (IkbkbGoF/GoF) results in dactylitis, spondylitis, and characteristic nail changes, which are features of psoriatic arthritis.”
“Using a mouse model, we identified that this mutation led to an abnormal function in a group of immune cells known as regulatory T cells,” explained Chelisa Cardinez, PhD, a postdoctoral fellow from the ANU John Curtin School of Medical Research (JCSMR).
“These cells are normally considered gatekeepers of the immune system. However, we found that this mutation alters the function of these cells, causing them to contribute to inflammation and promote the onset of disease.”
Cardinez said: “Studies have shown that delays in psoriatic arthritis diagnosis is linked to worse clinical outcomes for patients. Therefore, earlier detection and treatment of these immune diseases is key to improving health outcomes.”
“In summary, our results provide a molecular and cellular mechanism to explain a wound-healing model of psoriasis and psoriatic arthritis, linked by the magnitude of the NF-κB defect. Further evaluation of this pathway in human disease may be warranted,” the researchers concluded.
Developing a better understanding of the IKBKB gene and the role it plays in promoting the onset of these diseases could bring scientists one step closer to finding treatment.
