Effect of Tamm-Horsfall protein on chemoluminescence response of polymorphonuclear leukocytes to uropathogenic Escherichia coli.
Mannose residues on the outer membranes of polymorphonuclear leukocytes (PMNL) are capable of binding mannose-sensitive Escherichia coli. Tamm-Horsfall protein, a major urinary glycoprotein, has also been shown to bind mannose-sensitive E. coli via mannose-containing side chains. The effect of Tamm-Horsfall protein on the interaction between PMNL and mannose-sensitive E. coli was studied by measuring luminol-dependent chemoluminescence after bacterial stimulation. In the presence of 0.475, 4.75, 47.5, and 475 mg/l Tamm-Horsfall protein, chemoluminescence responses were reduced in a dose-dependent fashion by 8.7%, 38.1%, 60.3%, and 96.1%, respectively. Addition of 0.003 units/ml alpha-mannosidase reversed the effect of increasing concentrations significantly. Thus, urinary Tamm-Horsfall protein seems to compete with PMNL for mannose-sensitive E. coli in a mannose-sensitive fashion, thereby significantly reducing the role of PMNL as a defense mechanism in the urine of patients with urinary tract infection.
Reinhart
H
H
Division of Infectious Diseases, Wayne State University, Detroit, Michigan.
Obedeanu
N
N
Merzbach
D
D
Sobel
J D
JD
D004926:Escherichia coli / Q000276:immunology*; D010861:Fimbriae, Bacterial / Q000276:immunology; D006801:Humans; D008163:Luminescent Measurements; D008358:Mannose / Q000378:metabolism; D009088:Mucoproteins / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism / Q000382:microbiology*; D058949:Uromodulin
D009088:Mucoproteins; C548612:UMOD protein, human; D058949:Uromodulin; D008358:Mannose