BCR signalling induces BAFF-R expression through NF-kB pathway. The main factor inducing BAFF-r expression is c-rel. And this is a fundamental aspect of follicular B cell selection, survival, and activation. I am sending an article that will help you. Pay attention to the reference 15.

Article B Cell Receptor-Mediated Sustained c-Rel Activation Facilita...

Hi Adrian

TLR pathways can also be involved in activation:

TLR stimulation modifies BLyS receptor expression in follicular and marginal zone B cells. Treml LS, Carlesso G, Hoek KL, Stadanlick JE, Kambayashi T, Bram RJ, Cancro MP, Khan WN. J Immunol. 2007 Jun 15;178(12):7531-9

and upregulation can be attenuated:

FcgammaRIIB signals inhibit BLyS signaling and BCR-mediated BLyS receptor up-regulation.Crowley JE, Stadanlick JE, Cambier JC, Cancro MP. Blood. 2009 Feb 12;113(7):1464-73.

Hi Adrian,

Not sure if this is what you were after but in addition 2 back-to-back papers in JEM by Anselm Enders and Chris Goodnow (ENU mutant) and Bernd Schroder (knockout) described BAFF-R expression during T1 to T2 transition required the intramembrane peptidase SPPL2A.

References Bergmann et al J. Exp. Med. 2013 Vol. 210 No. 1 31-40 and Schneppenheim  et al J. Exp. Med. 2013 Vol. 210 No. 1 41-58.

Best,

Tri.