Objective:To study and confirm that recombinant cytokines similar to those produced by HIV-1 infected T cells induced lytic cycle replication of human pervirus 8(HHV-8) in BC-3 cells,another cell line from primary effusion lymphoma(PEL).Methods:The persistent stimulation of BC-3 was conducted by several cytokines known to be produced by HIV-1-infected T cells and important in grouth and proliferation of Kaposi's sarcoma(KS) cells in vitro,such as the inter feron-γ（IFN-γ）,the hepatocyte grouth factor /scatter factor (HGF/SF),the Oncostain M(OSM),and the tumor necrosis factor-α（TNF-α）which is not produced by HIV-1-infeted T cells.Treated and antrented BC-3 cells were collected at the 3rd and 7th day of persistent stimulation,respeclively.Immunohistochemical(IHC) staining. Northern blot,quantitative PCR(real-time PCR) and electron microscopy(EM) were carried out to detect the expression of immumogenic protein ORF59,messenger RNA(mRNA) of minor capsid protein ORF26,and the presence of viral particles of HHV-8 from treated and untreated BC-3 cells.Results:It showed that IFN-γ,HGF/SF/OSM,and TNF-α were found to induce an increase in mRNA expression of ORF26 when added individually to BC-3 cells.Particularly,ORF26 expression stimulated with IFN-γ and TNF-α respectively,increased 6.1 and 2.5-fold(from,real-time PCR results) at the 7th day when compared with untreated BC-3 cells.Meanwhile ,about 20% of IFN-γ stimulated BC-3 cells expressed ORF59 at the 7th day as compared with 1.5% of untreated BC-3 cells when IHC staining was employed.In addition,viral particles of HHV-8 were readily idelified in BC-3 cells stimulated with IFN-γ at the 7th day with EM analysis.Conclusion:TNF-α and recombinant cytokines being similar to those produced by HIV-1 infected T Cells could really induce HHV-8 lytic cycle replication in BC-3 cells,another cell line of PEL.
