HIDDEN ANTI-DOUBLE STRANDED DNA ANTIBODIES IN AUTOIMMUNE MICE

  • 1 January 1982
    • journal article
    • research article
    • Vol. 49  (3) , 587-597
Abstract
When MRL/l mouse spleen cell culture supernatants were incubated with normal mouse spleen cells, a 2-50-fold increase in anti-dsDNA [double stranded DNA] activity was noted. A smaller increase in anti-ssDNA [single stranded DNA] and no change in anti-TNP antibody activity were observed. This hidden antibody in the MRL/l supernatants could not be revealed by DNAase digestion and could not be absorbed by a DNA cellulose column. Hidden antibody was removed from supernatants by sepharose-anti-Ig. After DNAase digestion of the MRL/l supernatants, hidden anti-dsDNA could not be revealed by incubation with spleen cells. All the hidden activity was excluded by gel filtration on Sephacryl S-300 (MW > 300,000) but was banded in the low density protein area of CsCl- equilibrium density gradients. MRL/l mouse sera had hidden anti-dsDNA antibodies. Hidden antibodies were present in both the IgG and IgM classes. The revealed antibodies demonstrated impaired ability to bind Fc specific anti-Ig reagents suggesting that they were partially degraded during the incubation with mouse spleen cells. The hidden anti-dsDNA appears to represent a DNA-anti-dsDNA complex, perhaps of very high affinity. It may explain why anti-dsDNA but not anti-ssDNA antibodies are of pathological importance in SLE [systemic lupus erythematosus].