Further, the titer of auto-reactive IgG1 directly correlates with the severity of clinical signs and worsening prognosis in GBS.37,38 Macrophage infiltration is also most marked in DRGs, consistent with its weaker nerve blood barrier.39,40 This contrasts with our previous findings that C. jejuni mediated colitis in specific pathogen free mice is T cell, IFN-γ and IL-17 dependent20 and demonstrates how differential T cell maturation by different C. jejuni strains leads to different disease outcomes in a susceptible host. The gene discussed is IL17A; the disease is colitis.