Objective In order to provide experimental model for the research of Human hepatocellular carcinoma(HCC), characterize two newly human hepatocellular carcinoma cell lines established from fresh tumor tissues of two patients with HCC infected HBV.Methods The two cell lines were analyzed by morphology, double time, isoenzyme pedigree(LDH), AFP、HBsAg detection, karyotype analysis, heterotransplantation utilizing hematoxylin and eosin、ELISA、flow cytometry、Southern blot and so on. Results The two cell lines have been in continuous culture over 50 passages, which showed typical epithelial-like cells in morphology; the doubling time of cell population were found to be 19.5~59.2 hours,which showed aneuploidy and revealed chromosome average number ranging from 50 to 105. Hepatitis-B-virus(HBV)DNA was integrated in the genomes of XMS-1.No lines produced alpha-fetoprotein(AFP) and HBsAg at the protein level.Their LDH isenozyme spectrum were similar to those of embryonic liver and clinical hepatoma with the increase of the percentage of LDH-1(H-type); Cell cycle analysis showed that the ratio of cells in S、G2-M phase increased for the both cell lines compared with healthy human peripheral blood lymphocyte; LXY-1 produced solid tumors after subcutaneous heterotransplantation into nude mice and the tumor formation ratio of heterotransplantation were 100%.Conclusions The two cell lines maintained the biologic characteristics as human hepatocellular carcinoma, and will serve as a model for further studies of HCC.

Objective To study the effects of CTLA4-Ig on mu rine allergic contact dermatitis.Methods Mice were exposed to DNFB to induce allergic contact dermatitis and were i njected with CTLA4-Ig.Ear swelling was measured 24h after antigen challenge.Splenocytes from treated mice were assayed for their ability to prolif erate in response to DNFB or FITC stimulation in vitro.Results Profound inhibition of contact hypersensitivity response(CHS )was shown by 69.7%in mice treated with CTLA4-Ig compared with mice treate d with PBS control.CT-LA4-Ig-treated mice displayed DNFB-specific tolerance,but exhibited a vigorous immune response to FITC when re-sensitizing 14days after the fir st challenge.Adoptive transfer of l ymphocytes from CTLA4-Ig-treated mice could induce inhibition of CHS in recipien t mice.Conclusions CTLA4-Ig can inhibit CHS by blocking B7/CD28co-stimulatory pathway,which provides a new way to suppress typeⅣallergic reaction.[