Biomaterial Database

DNA-anti-DNA immune complexes. Antibody protection of a discrete DNA fragment from DNase digestion in vitro. 1984

W Emlen, and R Ansari, and G Burdick

We examined the ability of DNase I to digest DNA that was contained with DNA-anti-DNA immune complexes. IgG isolated from the sera of 20 patients with systemic lupus erythematosus (SLE) and containing antibodies to DNA was incubated with double-stranded DNA to form immune complexes. Excess DNase was added, and digestion of DNA was monitored by the conversion of DNA to TCA soluble products. IgG from 8 of the 20 SLE patients protected DNA from degradation by DNase in direct proportion to the amount of DNA bound to IgG as measured in the Farr binding assay. Using IgG from these sera, we showed that the DNA protected from degradation remained bound to IgG during digestion and was 35-45 base pairs in size. The size of this fragment is the same as that which has been proposed to be the minimal size necessary for monogamous bivalent binding of IgG to DNA. We therefore compared the ability of F(ab')2 and Fab' to protect DNA from DNase digestion and demonstrated that the bivalent F(ab')2 fragments were protective, but that the univalent Fab' fragments were not. These results suggest that some antibodies to DNA that bind to DNA via monogamous bivalent binding can protect a 35-45-base pair DNA fragment from DNase digestion. The implications of this finding are discussed with regard to the in vivo behavior and potential pathogenicity of small DNA-anti-DNA immune complexes.

UI	MeSH Term	Description	Entries
D007074	Immunoglobulin G	The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.	Gamma Globulin, 7S,IgG,IgG Antibody,Allerglobuline,IgG(T),IgG1,IgG2,IgG2A,IgG2B,IgG3,IgG4,Immunoglobulin GT,Polyglobin,7S Gamma Globulin,Antibody, IgG,GT, Immunoglobulin
D008180	Lupus Erythematosus, Systemic	A chronic, relapsing, inflammatory, and often febrile multisystemic disorder of connective tissue, characterized principally by involvement of the skin, joints, kidneys, and serosal membranes. It is of unknown etiology, but is thought to represent a failure of the regulatory mechanisms of the autoimmune system. The disease is marked by a wide range of system dysfunctions, an elevated erythrocyte sedimentation rate, and the formation of LE cells in the blood or bone marrow.	Libman-Sacks Disease,Lupus Erythematosus Disseminatus,Systemic Lupus Erythematosus,Disease, Libman-Sacks,Libman Sacks Disease
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D003850	Deoxyribonuclease I	An enzyme capable of hydrolyzing highly polymerized DNA by splitting phosphodiester linkages, preferentially adjacent to a pyrimidine nucleotide. This catalyzes endonucleolytic cleavage of DNA yielding 5'-phosphodi- and oligonucleotide end-products. The enzyme has a preference for double-stranded DNA.	DNase I,Streptodornase,DNA Endonuclease,DNA Nicking Enzyme,DNAase I,Dornavac,Endonuclease I,Nickase,Pancreatic DNase,T4-Endonuclease II,T7-Endonuclease I,Thymonuclease,DNase, Pancreatic,Endonuclease, DNA,T4 Endonuclease II,T7 Endonuclease I
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004706	Endodeoxyribonucleases	A group of enzymes catalyzing the endonucleolytic cleavage of DNA. They include members of EC 3.1.21.-, EC 3.1.22.-, EC 3.1.23.- (DNA RESTRICTION ENZYMES), EC 3.1.24.- (DNA RESTRICTION ENZYMES), and EC 3.1.25.-.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000906	Antibodies	Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).