White cell immunoglobulin-like receptor B4 (LILRB4) is a member of the leukocyte Ig-like receptor (LILRs) family. Under physiological conditions, LILRB4 plays a crucial role in the immune system by being expressed on various immune cells such as T cells and plasma cells. In pathological conditions, LILRB4 impacts the progression of various diseases, like tumor transformation and infiltration in leukemia, through multiple signaling pathways.
LILRB4 is predominantly expressed on antigen-presenting cells (APCs) as an immune tolerance receptor. Additionally, by inhibiting the expression of co-stimulatory molecules, LILRB4-expressing APCs play a critical role in regulating inflammation. Moreover, LILRB4-mediated neutralization can enhance antigen presentation.
Differential expression of LILRB4 is found in various immune system diseases such as Kawasaki disease, systemic lupus erythematosus (SLE), sepsis, and recent studies suggest its involvement in mental disorders. Given the significant role of LILRB4 in the immune system and its varied expression in multiple diseases, it emerges as a potential therapeutic target for diverse illnesses.
