LACTOFERRIN INTERACTS WITH DEOXYRIBONUCLEIC-ACID - A PREFERENTIAL REACTIVITY WITH DOUBLE-STRANDED DNA AND DISSOCIATION OF DNA ANTI-DNA COMPLEXES

  • 1 January 1982
    • journal article
    • research article
    • Vol. 99  (1) , 127-138
Abstract
LF [lactoferrin] bound to DNA as assessed by immunofluorescence studies on mouse liver 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 [ds] and single-stranded [ss] configurations; dsDNA eluted with a 0.69 M NaCl buffer, whereas ssDNA eluted with a 0.25 M 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.sbd.DNAse digestion alone liberated free LF. The interaction of LF with DNA partially inhibited the binding of anti-DNA antibodies from patients with SLE [systemic lupus erythematosus] as assayed in a standard Farr assay. DNA-anti-DNA (labeled with 125I-IgG) complexes could be dispersed in vitro by the addition of LF. 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.