The T cell Goodpasture epitope induces T cell reactivity to itself and to α3(IV)NC1 in HLA-DRB1*1501 Tg mice, but not HLA-DRB1*01:01 Tg mice deficient in FcγRIIb (1501 Tg.FcγRIIb−/− and 0101 Tg.FcγRIIb−/−, respectively) immunized with α3136–146. As expected, 1501 Tg mice develop reactivity to both α3136–146 and α3(IV)NC1 (proliferation A, IFN-γ ELISPOT B, IL-17A ELISPOT C). However, despite the presence of further autoimmunity susceptibility genes, lymphocytes from 0101 Tg mice are unresponsive to α3136–146 and α3(IV)NC1. ***P<0.001.