Identification of DNA-reactive B cells in patients with systemic lupus erythematosus.

Autoreactive B cells play a central role in systemic lupus erythematosus (SLE). Characterization of DNA-reactive B cells in the blood of lupus patients has been limited by the low frequency of the population. Using a tetrameric configuration of a peptide mimetope of DNA, we identified peptide-reactive B cells in peripheral blood. Antibodies derived from these B cells bound to peptide and were largely cross-reactive to dsDNA. This methodology enables us to track the development of autoreactive B cells, which recognize peptide and dsDNA, in individual patients with SLE and permits the isolation of autoreactive B cells for further characterization.