Production of Anti-DNA Antibody Producing Hybridoma Cells and Characterization of Anti-DNA Antibodies

Abstract

The pathogenesis of systemic lupus erythematosus (SLE) an autoimmune disease, is unknown, but it is certain that anti-DNA antibodies are closely related to pathogenesis. The character and combination of the isotype, antigen specificity and charge are thought to be main factors in pathogenesis; in effect, they determine the toxicity of anti-DNA antibodies. In this study, the spleen cells of MRL-lpr/lpr mouse were fused with P3X63Ag8.653 myeloma cells, to obtain hybridoma cells which secrete various anti-DNA antibodies. From these cells, anti-DNA antibodies were separated, purified and analysed. The findings are summarised as follows: 1) 14 hybridoma clones produced monoclonal anti-DNA antibodies. 2) 14 clones showed highly positive reaction to single-stranded DNA, and 4 clones out of the 14 clones showed cross-reaction between single-stranded DNA and double-stranded DNA. No clone reacted with left-handed Z DNA. 3) 13 clones out of the 14 clones had the isotype IgG2a, K ; the remaining clone had the isotype IgM, K . None of the clones had a A chain. 4) 6 clones showed positive reaction to poly[dA-dT] - poly[dA-dT] and poly[dA] ? poly[dT], 7 clones to poly[dA-dC] - poly[dG-dT], 8 clones to poly[dG-dC] and 2 clones had a positive reaction to poly[dG-dC] - poly[dG-dC]. 5) 3 clones showed negative charge of p13.6~7.2, 10 clones showed positive charge of p18.0~9.2 and the remaining clone had neutral charge of pI 7.0~7.4. Our findings suggest that 4 antibodies, which react with double-stranded DNA and have IgG2a isotype and cationic charge, may have pathogenic activity. This finding needs to be further tested by evaluating the effects of these antibodies when injected into normal young antoimmune disease-prone mice.