IgG glycosylation in autoimmune-prone strains of mice

The relationship between increased levels of IgG oligosaccharide chains lacking galactose (G0) and the development of rheumatoid arthritis is unclear. In order to further our understanding of the observed correlation between raised serum G0 and arthritis, we have studied G0 levels in arthritis-prone and non-susceptible (i.e. non-arthritis-prone) mice and the effects on G0 of mycobacterial antigens, which have been postulated to play a role in the early events leading to the development of arthritis. We have shown that different age-matched mouse strains have characteristic 'resting' levels of G0 which (in six out of seven strains of mice) increase with age. We have also shown that these increases can be enhanced by immunization of arthritis-prone strains of mice with an adjuvant containing mycobacteria (Freund's complete adjuvant (FCA)), suggesting that deflects in the ability to regulate these G0 changes may be related to susceptibility to arthritis.