title: Human herpesvirus-8-encoded LNA-1 accumulates in heterochromatin- associated nuclear bodies.
abstract: Subnuclear distribution of the human herpesvirus-8 (HHV-8)- encoded nuclear protein LNA-1 was analysed at high resolution in body cavity (BC) lymphoma-derived cell lines, in cell hybrids between BC cells and various human and mouse cells and in freshly infected K562 and ECV cell lines. Three-dimensional reconstruction of nuclei from optical sections and quantitative analysis of the distribution of LNA-1 fluorescence in relation to chromatin showed that LNA-1 associates preferentially with the border of heterochromatin in the interphase nuclei. This was further confirmed in the following systems: in endo- and exonuclease-digested nuclei, in human-mouse (BC-1-Sp2- 0) hybrids and on chromatin spreads. LNA-1 was found to bind to mitotic chromosomes at random. Epstein-Barr virus (EBV), but not HHV-8, was rapidly lost from mouse-human hybrid cells in parallel with the loss of human chromosomes. HHV-8 could persist on the residual mouse background for more than 8 months. In early human-mouse hybrids that contain a single fused nucleus, LNA-1 preferentially associates with human chromatin. After the gradual loss of the human chromosomes, LNA-1 becomes associated with the murine pericentromeric heterochromatin. In human-human hybrids derived from the fusion of the HHV-8-carrying BCBL-1 cells and the EBV-immortalized lymphoblastoid cell line IB4, LNA-1 did not co-localize with EBNA-1, EBNA-2, EBNA-5 or EBNA-6. LNA-1 was not associated with PML containing ND10 bodies either. DNase but not RNase or detergent treatment of isolated nuclei destroys LNA-1 bodies. In advanced apoptotic cells LNA- 1 bodies remain intact but are not included in the apoptotic bodies themselves.
authors.affiliation: Microbiology and Tumor Biology Center, Karolinska Institute, S171 77, Stockholm, Sweden1.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Szekely
authors.affiliation: Microbiology and Tumor Biology Center, Karolinska Institute, S171 77, Stockholm, Sweden1.
authors.forename: Csaba
authors.initials: C
authors.lastname: Kiss
authors.affiliation: Microbiology and Tumor Biology Center, Karolinska Institute, S171 77, Stockholm, Sweden1.
authors.forename: Karin
authors.initials: K
authors.lastname: Mattsson
authors.affiliation: Microbiology and Tumor Biology Center, Karolinska Institute, S171 77, Stockholm, Sweden1.
authors.forename: Elena
authors.initials: E
authors.lastname: Kashuba
authors.affiliation: Microbiology and Tumor Biology Center, Karolinska Institute, S171 77, Stockholm, Sweden1.
authors.forename: Katja
authors.initials: K
authors.lastname: Pokrovskaja
authors.affiliation: Department of Microbiology, University Medical School of Debrecen, H-4012 Debrecen, Hungary2.
authors.forename: Attila
authors.initials: A
authors.lastname: Juhasz
authors.affiliation: Microbiology and Tumor Biology Center, Karolinska Institute, S171 77, Stockholm, Sweden1.
authors.forename: Pia
authors.initials: P
authors.lastname: Holmvall
authors.affiliation: Microbiology and Tumor Biology Center, Karolinska Institute, S171 77, Stockholm, Sweden1.
authors.forename: George
authors.initials: G
authors.lastname: Klein
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000032:analysis*; D017209:Apoptosis; D002460:Cell Line; D002467:Cell Nucleus / Q000737:chemistry*; D002875:Chromosomes / Q000737:chemistry; D019309:Epstein-Barr Virus Nuclear Antigens / Q000032:analysis; D019288:Herpesvirus 8, Human / Q000737:chemistry*; D006570:Heterochromatin / Q000737:chemistry*; D006801:Humans; D006822:Hybrid Cells; D008677:Metaphase; D051379:Mice; D009687:Nuclear Proteins / Q000032:analysis*; D010750:Phosphoproteins
chemical_list: D000956:Antigens, Viral; D019309:Epstein-Barr Virus Nuclear Antigens; D006570:Heterochromatin; D009687:Nuclear Proteins; D010750:Phosphoproteins; C118485:latent nuclear antigen (LNA)