Pharmacological inhibition of TLR9 activation blocks autoantibody production in human B cells from SLE patients

Toll-like receptor 9 (TLR9), which recognizes hypomethylated DNA [cytosine-phosphate-guanine (CpG)], plays a role in the maintenance of serological memory and has been recently implicated in the pathogenesis of SLE. We previously reported that in vitro TLR9 triggers memory B-cell differentiation into antibody-producing cells, and that the MyD88-inhibitor ST2825 blocks TLR9-induced plasma cell (PC) generation. Here, we investigated whether memory B cells produce autoantibodies in SLE patients with active disease or in clinical remission, and whether ST2825 could inhibit PC generation in SLE patients