EXPRESSION OF THE HEPATITIS-B SURFACE-ANTIGEN (HBSAG) UNDER THE CONTROL OF MMT-I PROMOTER IN TRANSGENIC MICE CAN BE INDUCED BY ZINC-SULFATE, DEXAMETHASONE AND LIPOPOLYSACCHARIDE

Metallothionein genes can be induced in vivo by heavy metals, glucocor ticoids, and toxins. In all transgenic mice carrying the MT-I promoter , that have been reported so far, induction by glucocorticoids failed. This study reports two mouse lines, transgenic for the murine MT-I-HB V (hepatitis B virus; map position site: 30-1986) construct, which sec rete the viral surface antigen (HBsAg) in their serum. In both lines, males produce more HBsAg than females, and in all cases the MT-I promo ter can be induced by dexamethasone, lipopolysaccharide (LPS), and hea vy metals. A glucocorticoid-responsive element, which is situated in t he HBV fragment used, can explain the dexamethasone induction of the M T-I promoter.