Compose LI(L)RA1 ballad: enlighten its role in cutaneous lupus erithematosus

This project has been funded thanks to the Joint Call Fondazione Cariplo and Fondazione Telethon 2022 

B lymphocytes are specialized cells of the immune system that can produce large amounts of antibodies. Antibodies are soluble proteins that can protect us from infections with pathogens, but when they react with structures of our own body they can induce tissue damage and autoimmune diseases. These self-reactive “autoantibodies” are indeed characteristic for patients with cutaneous lupus erythematosus (CLE), an autoimmune disease where the skin is attacked by the immune system. B lymphocytes are overreactive in CLE patients, produce consequently autoantibodies, and these autoantibodies are likely to promote inflammation of the skin. B-lymphocytes express the receptor LILRA1, whose function is largely unknown. However, based on its structure and the knowledge on receptors that belong to the same family, it can be predicted that it promotes the activation of B lymphocytes. LILRA1 is associated with CLE, and we therefore propose to investigate its role in B lymphocyte activation, autoantibody production and CLE. Thus, we will first compare the expression of LILRA1 and other relevant LILR family members on B lymphocytes and other LILR-expressing immune cells in healthy individuals and CLE patients. We will further investigate if LILRA1 promotes, as predicted, B lymphocyte activation and antibody production. We will finally assess if LILR1A-expressing B lymphocytes from CLE patients produce indeed autoantibodies. Targeting receptors that regulate the activation of lymphocytes was a recent major breakthrough in cancer therapy, and it is also used in some autoimmune diseases. LILRA1 may thus be targeted to treat CLE and/or other autoimmune diseases in the future.