Identification of hBD-3 in respiratory tract and serum: the increase in pneumonia.
Human beta-defensin (hBD)-3, a 45 amino acid antimicrobial peptide, was originally isolated from human skin. hBD-3 mRNA has also been detected in the airways by RT-PCR. While hBD-3 may be involved in antimicrobial defences within the respiratory tract, the presence of hBD-3 peptide in the respiratory system has not yet been confirmed. The antimicrobial activity of the synthesised hBD-3 peptide was measured by a radial diffusion assay and a colony count assay. The present authors confirmed the presence of hBD-3 peptide in homogenates of human lung and serum using reverse-phase HPLC coupled with a highly sensitive RIA. The localisation of the hBD-3 peptide was investigated by immunohistochemistry. In addition, the serum concentrations of hBD-3 were measured by RIA. hBD-3 exhibited a strong antimicrobial activity, which was unaffected by increasing salt concentrations. Immunohistochemically, the current authors observed the expression of hBD-3 in bronchial and bronchiolar epithelial cells. The mean+/-sd serum concentration of hBD-3 in patients with bacterial pneumonia was 239.4+/-17.8 pg x mL(-1) in the acute phase and, decreased to 159.3+/-20.1 pg x mL(-1) after the completion of therapy. In conclusion, these findings will help elucidate the role of human beta-defensin-3 in host immune responses and identify the pathophysiological significance of this molecule in respiratory infections.
Ishimoto
H
H
Second Dept of Internal Medicine, Nagasaki University School of Medicine, Japan.
Mukae
H
H
Date
Y
Y
Shimbara
T
T
Mondal
M S
MS
Ashitani
J
J
Hiratsuka
T
T
Kubo
S
S
Kohno
S
S
Nakazato
M
M
D000328:Adult; D000368:Aged; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000378:metabolism*; D011863:Radioimmunoassay; D012137:Respiratory System / Q000378:metabolism*; D023083:beta-Defensins / Q000097:blood / Q000378:metabolism* / Q000494:pharmacology
C422950:DEFB103A protein, human; D023083:beta-Defensins