title: Lactoferrin interacts with deoxyribonucleic acid: a preferential reactivity with double-stranded DNA and dissociation of DNA-anti-DNA complexes.
abstract: LF was found to bind to deoxyribonucleic acid as assessed by immunofluorescence studies on cell nuclei, affinity chromatography of DNA on immobilized LF, and gel chromatography of an LF-DNA reaction mixture. LF immobilized on Sepharose 4-B was reacted with 125I-labeled DNA in both its double-stranded and single-stranded configurations; dsDNA eluted with a 0.69M NaCl buffer, whereas ssDNA eluted with a 0.25M NaCl buffer. Additional evidence for a preferential reactivity with dsDNA was provided by the enzymatic treatment of preformed dsDNA-LF and ssDNA-LF complexes with S1 endonuclease, and DNAse 1--DNase digestion alone liberated free LF. The interaction of LF with DNA partially inhibited the binding of anti-DNA antibodies from patients with SLE, as assayed in a standard Farr assay. Furthermore, DNA-anti-DNA (labeled with 125I-IgG) complexes could be dispersed in vitro by the addition of LF. It is hypothesized that the release of LF by neutrophils chemotactically attracted to DNA-anti-DNA complexes may act as a feedback loop to modulate the inflammatory response in SLE.
mesh_terms: D000936:Antigen-Antibody Complex / Q000378:metabolism*; D001665:Binding Sites; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D004247:DNA / Q000276:immunology* / Q000378:metabolism; D003851:Deoxyribonucleases / Q000494:pharmacology; D004720:Endonucleases / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D006801:Humans; D005779:Immunodiffusion; D007158:Immunologic Techniques; D007781:Lactoferrin / Q000378:metabolism*; D007782:Lactoglobulins / Q000378:metabolism*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology / Q000378:metabolism; D015719:Single-Strand Specific DNA and RNA Endonucleases
chemical_list: D000936:Antigen-Antibody Complex; D007782:Lactoglobulins; D004247:DNA; D003851:Deoxyribonucleases; D004720:Endonucleases; D015719:Single-Strand Specific DNA and RNA Endonucleases; D007781:Lactoferrin