Hidden anti-double stranded DNA antibodies in autoimmune mice.
When MRL/l mouse spleen cell culture supernatants were incubated with normal mouse spleen cells, a two-50-fold increase in anti-dsDNA activity was noted. A smaller increase in anti-ssDNA and no change in anti-TNP antibody activity were observed. This 'hidden' antibody in the MRL/l supernatants could not be revealed by DNAse 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 (mol. wt greater than 300,000) but was banded in the low density protein area of caesium chloride equilibrium density gradients. It was also noted that 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 thus 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.
D000818:Animals; D000974:Antibodies, Antinuclear / Q000032:analysis*; D000936:Antigen-Antibody Complex; D001323:Autoantibodies / Q000032:analysis*; D004247:DNA / Q000276:immunology*; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007158:Immunologic Techniques; D051379:Mice; D008815:Mice, Inbred Strains; D008968:Molecular Conformation; D013154:Spleen / Q000166:cytology / Q000276:immunology
D000974:Antibodies, Antinuclear; D000936:Antigen-Antibody Complex; D001323:Autoantibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D004247:DNA