Identification of human beta-defensin-2 in respiratory tract and plasma and its increase in bacterial pneumonia.
Human beta-defensin-2 (hBD-2), a novel antimicrobial peptide, was originally isolated from human skin. We found that synthetic hBD-2 has high bactericidal activity against Escherichia coli under conditions nearly the same as in human bronchial airway surface liquid. We prepared an antiserum against hBD-2 and established a highly sensitive radioimmunoassay (RIA). Reverse-phase high-performance liquid chromatography coupled with the RIA showed that hBD-2 in patients with human lung, bronchoalveolar lavage flid, and plasma. The plasma concentration of hBD-2 in patients with bacterial pneumonia was 32.1 +/- 3.7 fmol/ml (mean +/- SE), 3.9-fold that of normal individuals. By reverse transcription-polymerase chain reaction, the hBD-2 gene transcript was detected in the respiratory epithelial surface of human lung. Human beta-defensin-2 seems to function in airway mucosal defense. Our findings provide a clue to elucidate its pathophysiological significance in respiratory infection.
Hiratsuka
T
T
Third Department of Internal Medicine, Miyazaki Medical College, Japan.
Nakazato
M
M
Date
Y
Y
Ashitani
J
J
Minematsu
T
T
Chino
N
N
Matsukura
S
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000378:metabolism; D001483:Base Sequence; D001770:Blood Bactericidal Activity / Q000235:genetics / Q000502:physiology; D001798:Blood Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D017931:DNA Primers / Q000235:genetics; D023082:Defensins; D004926:Escherichia coli / Q000276:immunology / Q000472:pathogenicity; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008168:Lung / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012137:Respiratory System / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology
D000900:Anti-Bacterial Agents; D001798:Blood Proteins; D017931:DNA Primers; D023082:Defensins; D012333:RNA, Messenger