Background: Network perturbations have been reported in autoimmune processes which could cause polyclonal cell activation.
Materials and methods: Hyper-immunization was achieved by the injection of 3 mg of human monoclonal IgM DJ into BALB/c mice. Indirect ELISA was performed to detect induced antibody specificities. Competitive ELISAs were carried out on sera to detect the idiotypes expressed in first (Ab1) and second (Ab2) antibodies in sequence.
Results: In the sera of hyper-immunized mice, the concentrations of Ab1 and Ab2 were respectively five and ten times higher than in the sera of normoimmunized mice. Polyclonal lymphocyte activation was demonstrated by an increase in antibodies specific for antigens (cytochrome C) not related to the immunizing antigen, elevated levels of IgM antibodies specific for the immunogen and elevated levels of Ab2s of the IgM isotype.
Conclusion: These findings are indicative of antigen-dependent network perturbation being a causative factor in polyclonal lymphocyte activation.