Association of low levels of mannan-binding protein with a common defect of opsonisation.
Failure to opsonise bakers' yeast (Saccharomyces cerevisiae) is a defect found in 5-7% of the general population. In this study, the presence of the defect was linked with low levels of mannan-binding protein (MBP), a calcium-dependent serum lectin. Purified MBP corrected the defect in a dose-dependent way in an in-vitro assay measuring the deposition of complement moieties on a mannan-coated surface. There was a highly significant correlation between the serum MBP level and the generation of C3b opsonins in a population of healthy blood donors. The median MBP level of ten children previously shown to have the functional opsonic defect was 4.9 micrograms/l (range 2.5-35.0 micrograms/l) compared with 143 micrograms/l (range 2.5-880 micrograms/l) for a paediatric control group.
Super
M
M
Department of Immunology, University of London.
Thiel
S
S
Lu
J
J
Levinsky
R J
RJ
Turner
M W
MW
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002352:Carrier Proteins / Q000097:blood* / Q000276:immunology / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D037222:Collectins; D003179:Complement C3b / Q000172:deficiency* / Q000378:metabolism; D003181:Complement C4 / Q000172:deficiency / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D015151:Immunoblotting; D007074:Immunoglobulin G / Q000302:isolation & purification; D007223:Infant; D008297:Male; D009895:Opsonin Proteins / Q000172:deficiency* / Q000378:metabolism; D010587:Phagocytosis / Q000502:physiology*
D002352:Carrier Proteins; D037222:Collectins; D003181:Complement C4; D007074:Immunoglobulin G; D009895:Opsonin Proteins; D003179:Complement C3b