RT Journal Article SR Electronic(1) A1 Oefinger, Paul E. A1 Bronson, David L. A1 Dreesman, Gordon R.YR 1981 T1 Induction of Hepatitis B Surface Antigen in Human Hepatoma-derived Cell Lines JF Journal of General Virology, VO 53 IS 1 SP 105 OP 113 DO https://doi.org/10.1099/0022-1317-53-1-105 PB Microbiology Society, SN 1465-2099, AB Summary Cultures of two human hepatoma cell lines were examined for expression of hepatitis B virus surface antigen (HBsAg). The PLC/PRF/5 cells secreted HBsAg continuously into the culture medium, whereas Mahlavu cells did not secrete the antigen. However, cytoplasmic antigen was detected in a low percentage (<5%) of the Mahlavu cells. The expression of HBsAg also was assayed in cultures treated with dexamethasone (DXM), 5-iodo-2′-deoxyuridine (IdUrd), or both. The results demonstrated that: (i) DXM stimulated secretion of HBsAg by PLC/PRF/5 cells but not by Mahlavu cells; (ii) the percentage of Mahlavu cells expressing cytoplasmic HBsAg was not increased in any cultures if the medium was replaced at 24 to 48 h intervals but was increased approx. fivefold within 4 days in cultures treated with DXM or IdUrd/DXM if the medium was not changed. However, no increase was noted in the intensity of the immunoperoxidase stain of PLC/PRF/5 cells that expressed cytoplasmic antigen in any DXM cultures; (iii) HBsAg expression was stimulated to a lesser extent in IdUrd/DXM cultures than in DXM cultures and was not enhanced in IdUrd cultures. Thus, DXM enhanced secretion of HBsAg by PLC/PRF/5 cells within 24 h and, after a delay, enhanced expression of cytoplasmic antigen by Mahlavu cells. However, antigen secretion by Mahlavu cells evidently was blocked., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-53-1-105