[Preliminary study of the molecular regulation of BCG-mediated enhancement of hBD-1 gene expression in human pulmonary gland epithelial cells].

OBJECTIVE:To define the regulation mechanism of the enhancement expression of human beta-defensin-1 (hBD-1) stimulated by bacille Calmette-Guerin (BCG) at transcription level. METHODS:A series of 5'-flanking deletions of hBD-1 gene were ligated into pEGFP-1 and pCAT basic vector. pEGFP hBD-1 recombinants were transfected into SPC-A-1 cells and the green fluorescence protein (GFP) expression was observed by fluorescence microscopy. SPC-A-1 cells were co-transfected with pCAT hBD-1 constructs and pSV-beta-Galactosidase control vector and were stimulated with effective BCG cell wall components. CAT and beta-Gal protein expressions were determined by ELISA. RESULTS:The promoting activity of the -69 region was lower than that of the region -575 and -314. After being stimulated with the active fraction of BCG cell wall proteins, the relative CAT expression of pCAT hBD-1/-69 still showed the increasing tendency of -2161 construct. Computer consensus match analysis indicated that the nucleotides between -63 bp to -50 bp was the potential binding site for C/EBP beta. CONCLUSION:The nucleotides from -69 to bp is essential to the enhancement of hBD-1 gene transcription by BCG.