Circulating anti-(xanthine oxidoreductase) antibodies in healthy human adults.
Levels of free anti-(xanthine oxidoreductase) (XOR) antibodies in the serum of normal healthy human subjects were determined, using both human and bovine enzyme as antigen, in an enzyme-linked immunosorbent assay (ELISA). Levels of IgM class anti-(human XOR) antibodies were found to be particularly high (mean values representing approximately 3% of total IgM) and to be significantly higher than levels of IgM anti-(bovine XOR) antibodies, indicating that endogenous XOR, rather than ingested bovine milk XOR, is the immunogen. IgM anti-XOR antibody levels were significantly higher in women under 50 years than in age-matched men, or in older women. Levels of IgG class anti-XOR antibodies were much lower and showed no correlation with gender or age. Affinity-purified anti-(human XOR) antibodies only partially inhibited enzymic activities of XOR. The majority of both IgM and IgG anti-(human XOR) antibodies in serum occurred as immune complexes, suggesting that the specific antibodies have a protective role in removing potentially damaging XOR from the circulation.
Benboubetra
M
M
School of Biology and Biochemistry, University of Bath, UK.
Gleeson
A
A
Harris
C P
CP
Khan
J
J
Arrar
L
L
Brennand
D
D
Reid
J
J
Reckless
J D
JD
Harrison
R
R
D000328:Adult; D000368:Aged; D000818:Animals; D000906:Antibodies / Q000097:blood* / Q000502:physiology; D000936:Antigen-Antibody Complex / Q000097:blood; D002417:Cattle; D004791:Enzyme Inhibitors / Q000097:blood / Q000276:immunology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors / Q000276:immunology*
D000906:Antibodies; D000936:Antigen-Antibody Complex; D004791:Enzyme Inhibitors; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D014969:Xanthine Oxidase