Evidence in patients with systemic lupus erythematosus of the presence of antibodies against RNA-dependent DNA polymerase of baboon endogenous virus.
Immunoglobulin G (IgG) in six out of 30 patients with systemic lupus erythematosus (SLE) strongly inhibited the activity of RNA-dependent DNA polymerase (RDPase) of baboon endogenous virus, M7, while IgG obtained from scleroderma patients, rheumatoid arthritis patients and normal subjects was less reactive. Experiments with anti-human IgG and with IgG F (ab')2-bound immunoaffinity columns indicated that the inhibition of RDPase was antibody-mediated. The RDPase inhibiting activity of SLE IgG was considered not to be due to cross-reactions of anti-nuclear antibodies including anti-DNA, anti-ribonucleoprotein, anti-Sm and anti-SS.B antibodies. SLE IgG preferably inhibited the RDPase activity of baboon endogenous virus and a feline endogenous virus, RD114. These findings support the hypothesis that retrovirus(es) might be involved in SLE.
D000818:Animals; D000974:Antibodies, Antinuclear / Q000032:analysis; D000914:Antibodies, Viral / Q000032:analysis*; D001172:Arthritis, Rheumatoid / Q000276:immunology; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D007141:Immunoglobulin Fc Fragments / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D010215:Papio; D012194:RNA-Directed DNA Polymerase / Q000276:immunology*; D012190:Retroviridae / Q000201:enzymology*; D012595:Scleroderma, Systemic / Q000276:immunology
D000974:Antibodies, Antinuclear; D000914:Antibodies, Viral; D007140:Immunoglobulin Fab Fragments; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D012194:RNA-Directed DNA Polymerase