BAFF and MyD88 signals promote a lupuslike disease independent of T cells

Joanna R Groom, Carrie A Fletcher, Stacey N Walters, Shane T Gray, Sally V Watt, Mathew J Sweet, Mark J Smyth, Charles Reay Mackay, Fabienne Mackay-Fisson

Research output: Contribution to journalArticleResearchpeer-review

274 Citations (Scopus)


Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by the production of autoantibodies. However, the underlying cause of disease appears to relate to defects in T cell tolerance or T cell help to B cells. Transgenic (Tg) mice overexpressing the cytokine B cell-activating factor of the tumor necrosis factor family (BAFF) develop an autoimmune disorder similar to SLE and show impaired B cell tolerance and altered T cell differentiation. We generated BAFF Tg mice that were completely deficient in T cells, and, surprisingly, these mice developed an SLE-like disease indistinguishable from that of BAFF Tg mice. Autoimmunity in BAFF Tg mice did, however, require B cell-intrinsic signals through the Toll-like receptor (TLR)-associated signaling adaptor MyD88, which controlled the production of proinflammatory autoantibody isotypes. TLR7/9 activation strongly up-regulated expression of transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI), which is a receptor for BAFF involved in B cell responses to T cell-independent antigens. Moreover, BAFF enhanced TLR7/9 expression on B cells and TLR-mediated production of autoantibodies. Therefore, autoimmunity in BAFF Tg mice results from altered B cell tolerance, but requires TLR signaling and is independent of T cell help. It is possible that SLE patients with elevated levels of BAFF show a similar basis for disease.
Original languageEnglish
Pages (from-to)1959 - 1971
Number of pages13
JournalJournal of Experimental Medicine
Issue number8
Publication statusPublished - 2007
Externally publishedYes

Cite this