Leukocyte immunoglobulin-like receptors as new players in autoimmunity

Leukocyte immunoglobulin-like receptors (LILR) are a family of at least 13 receptors mainly expressed on lymphoid and myelomonocytic cells. They are involved in the activation of the immune system. Inhibitory LILR (termed LILRB) signal through immunoreceptor tyrosine-based inhibitory motives in the cytoplasmic domain, whereas LILRA with short cytoplasmic domains are stimulatory receptors. Polymorphisms and deletions of leukocyte immunoglobulin-like receptors have been shown to be associated with autoimmune disorders, and some of the receptors are involved in the generation of regulatory T cells. Therefore, leukocyte immunoglobulin-like receptors may be central in the pathogenesis of autoimmunity. The data linking these receptors to autoimmune diseases is reviewed here.