Our results show that lupus IgG1 injection could significantly increase serum anti-nuclear IgG1 levels in MRL-lpr/lpr mice through 19 weeks and that the increase in anti-nuclear IgG3 and anti-dsDNA IgG3 at 19 weeks of age were significantly inhibited in MRL-lpr/lpr mice treated with control IgG1 and non-treated groups. Here, IGHG3 is linked to systemic lupus erythematosus.