title: Reappraisal of the specificity of the Crithidia luciliae assay for nDNA antibodies: evidence for histone antibody kinetoplast binding.
abstract: Five different high-titer histone antibody-containing sera were assayed by the Crithidia luciliae indirect immunofluorescence (CLIF) technic. Three of these sera produced kinetoplast binding at titers of 1/40 to 1/80. The kinetoplast binding activity was abolished by HCl acid pretreatment of the Crithidia substrate, suggesting that the kinetoplast binding activity was not due to antibodies against native DNA (nDNA). Histone antibodies were purified from two of the three positive sera by affinity chromatography utilizing purified preparations of histone. Both purified antibody preparations also had kinetoplast-binding activity, confirming that the Crithidia kinetoplast contains histone-like proteins. Therefore, Crithidia luciliae (CL) kinetoplast binding activity does not necessarily indicate the presence of anti-nDNA antibodies. Routinely pretreating the CL substrate with 0.1 N HCl would eliminate the possibility of histone antibody kinetoplast binding in the CLIF assay. Whether such pretreatment would alter the binding of anti-NDNA to the kinetoplast remains to be determined.
mesh_terms: D000906:Antibodies / Q000032:analysis*; D000974:Antibodies, Antinuclear / Q000032:analysis*; D003421:Crithidia; D004247:DNA / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D006657:Histones / Q000276:immunology*; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008722:Methods
chemical_list: D000906:Antibodies; D000974:Antibodies, Antinuclear; D006657:Histones; D004247:DNA