1/5. Inheritance of chromosomally integrated human herpesvirus 6 dna.Human herpesvirus 6 (HHV-6) genome has been detected in several human lymphoproliferative disorders with no signs of active viral infection, and found to be integrated into chromosomes in some cases. We previously reported a woman with HHV-6-infected Burkitt's lymphoma. fluorescence in situ hybridization showed that the viral genome was integrated into the long arm of chromosome 22 (22q13). The patient's asymptomatic husband also carried HHV-6 dna integrated at chromosome locus 1q44. To assess the possibility of chromosomal transmission of HHV-6 dna, we looked for HHV-6 dna in the peripheral blood of their daughter. She had HHV-6 dna on both chromosomes 22q13 and 1q44, identical to the site of viral integration of her mother and father, respectively. The findings suggested that her viral genomes were inherited chromosomally from both parents. The 3 family members were all seropositive for HHV-6, but showed no serological signs of active infection. To confirm the presence of HHV-6 dna sequences, we performed polymerase chain reaction (PCR) with 7 distinct primer pairs that target different regions of HHV-6. The viral sequences were consistently detected by single-step PCR in all 3 family members. We propose a novel latent form for HHV-6, in which integrated viral genome can be chromosomally transmitted. The possible role of the chromosomally integrated HHV-6 in the pathogenesis of lymphoproliferative diseases remains to be explained.- - - - - - - - - - ranking = 1keywords = herpesvirus (Clic here for more details about this article) |
2/5. Nonmalignant disease associated with human herpesvirus 8 reactivation in patients who have undergone autologous peripheral blood stem cell transplantation.fever, cutaneous rash, and hepatitis-for which an infectious cause was suspected-developed in an Italian patient with non-Hodgkin lymphoma after autologous peripheral blood stem cell (PBSC) transplantation. polymerase chain reaction (PCR) with degenerate primers for the highly conserved dna polymerase gene of herpesviruses detected herpesvirus sequences 100% identical to human herpesvirus-8 (HHV-8) in serial cell-free serum samples, collected immediately before or concomitant with the occurrence of clinical symptoms; no other common infections were documented. The presence of the HHV-8 genome (clade C) was confirmed by PCR with HHV-8-specific primers for orf 26 and orf-K1. HHV-8 viremia was undetectable either before transplantation or when the patient was clinically asymptomatic. Semiquantitative PCR analysis showed variations of the viral load correlating with the clinical status. Anti-HHV-8 antibodies were detected before and after transplantation by an immunofluorescence assay for lytic antigens. Active HHV-8 infection may be associated with nonmalignant illness after PBSC/bone marrow transplantation.- - - - - - - - - - ranking = 1.4keywords = herpesvirus (Clic here for more details about this article) |
3/5. Isolation of a herpesvirus-specific dna polymerase from tissues of an American patient with burkitt lymphoma.A dna polymerase (dna nucleotidyltransferase) has been partially purified from a neck mass of an American patient with burkitt lymphoma and separated from the cellular dna polymerases. The molecular weight of the enzyme was approximately 90,000. The enzyme differs from the cellular dna polymerases, but resembles herpes-virus-induced dna polymerase in its primer template preference, high monovalent cation requirement for activity, and sensitivity to phosphonoacetate. Enzyme activity was inhibited specifically by an antibody directed against herpes-simplex-virus-induced dna polymerase but not by antibodies directed against dna polymerase alpha of hela cells and dna polymerase gamma of a normal human lymphoblast cell line, NC37. Although serum of the patient with burkitt lymphoma contained high Epstein-Barr virus titer, addition of the serum to the assay mixture did not have any effect on the activity of burkitt lymphoma dna polymerase. tissues from spleen and liver of the patient with burkitt lymphoma did not contain the herpes-virus-induced dna polymerase. Detection of the herpes virus polymerase in the burkitt lymphoma tissue provides additional evidence for the association of Epstein-Barr virus with this malignancy.- - - - - - - - - - ranking = 0.8keywords = herpesvirus (Clic here for more details about this article) |
4/5. Primary effusion Burkitt's lymphoma with t(8;22) in a patient with hepatitis c virus-related cirrhosis.hepatitis c virus (HCV) infection may be complicated by non-Hodgkin's lymphoma through yet unknown pathogenetic mechanisms. We describe the case of a patient with HCV-related cirrhosis who developed a primary effusion lymphoma (PEL) of Burkitt's type confined to the peritoneal cavity, in the absence of immunodeficiency or autoimmunity. paracentesis followed by immunophenotyping, karyotyping, and molecular studies allowed us to diagnose a small noncleaved B-cell lymphoma (CD20 , CD24 , CD10 , CD5-, CD23-, lambda ) with the t(8;22) (q24;q11) translocation and clonal rearrangement of the immunoglobulin heavy chain gene. HCV-rna, Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus were not identified within lymphoma cells. The finding of HCV-rna in the ascitic fluid suggests a link between HCV and development of lymphoma with HCV playing the role of persistent antigenic stimulation to intraperitoneal B-cell clonal expansion(s).- - - - - - - - - - ranking = 0.2keywords = herpesvirus (Clic here for more details about this article) |
5/5. Human herpesvirus 6 (HHV-6)-positive Burkitt's lymphoma: establishment of a novel cell line infected with HHV-6.Human herpesvirus 6 (HHV-6) dna has been detected in several human lymphoproliferative disorders. We report a case of HHV-6-infected Burkitt's lymphoma, from which a cell line, designated Katata, has been established. Katata cells had an immature B-cell phenotype with an L3 morphology and carried a t(8;14)(q24;q32) chromosomal abnormality. The HHV-6 dna sequences were detected in both the patient's tumor cells and Katata cell line by polymerase chain reaction using three sets of primers that target different regions of HHV-6 dna. The presence of HHV-6 dna in Katata cells was also shown by Southern blot hybridization with the BamHI fragment of HHV-6. It is likely that the virus is in a latent state, since (1) virion-associated protein was not expressed in Katata cells, (2) transcriptional level of the immediate-early gene was very low, and (3) no viral particles were observed by electron microscopy. Katata cells were highly tumorigenic in nude mice and the tumor cells also contained HHV-6 dna. We have successfully obtained several clonal lines by allowing the cells to form colonies in soft agarose and by the limiting dilution method. HHV-6 dna was detectable in all 13 clones analyzed, suggesting that virtually all Katata cells are infected with HHV-6. This is the first report of a case of HHV-6 Burkitt's lymphoma in the absence of Epstein-Barr virus. Furthermore, there has been no report of lymphoma cell lines that are persistently and nonproductively infected with HHV-6. The Katata Burkitt's lymphoma cell line, therefore, would provide a useful tool for studies of the mechanisms of HHV-6 latency and reactivation.- - - - - - - - - - ranking = 1keywords = herpesvirus (Clic here for more details about this article) |