Lymphoblastoid cell lines with integrated human herpesvirus type 6.
OBJECTIVE
Attempts were made to establish stable in vitro cell lines latently infected with human herpesvirus type 6 (HHV-6).


METHODS
We previously studied a patient with B-cell acute lymphoblastic leukemia infected with HHV-6. The peripheral blood mononuclear cells (PBMCs) from this patient were immortalized by infection with Epstein-Barr virus (EBV) and herpesvirus saimiri (HVS).


RESULTS
Infection of the PBMCs with EBV and HVS gave rise to B- and T-lymphoblastoid cell lines, respectively. Both cell lines were positive for HHV-6 DNA, as confirmed by polymerase chain reaction (PCR) and Southern blot hybridization. Fluorescence in situ hybridization (FISH) demonstrated integration of HHV-6 in these cell lines. Only one integrated site of viral DNA was detected in metaphase chromosome spreads, and it was preferentially located at the long arm of chromosome 1 (1q44). HHV-6 appeared latent in the infected cells, since neither the HHV-6 immediate-early gene transcript nor virion-associated protein was detected.


CONCLUSIONS
The HHV-6-positive lymphoblastoid cell lines would be useful for study of the mechanism of HHV-6 integration.
Daibata
M
M
Department of Medicine, Kochi Medical School, Japan. daibatam@kochi-ms.ac.jp
Taguchi
T
T
Kubonishi
I
I
Taguchi
H
H
Miyoshi
I
I
D000368:Aged; D000369:Aged, 80 and over; D015139:Blotting, Southern; D002460:Cell Line / Q000821:virology*; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D004854:Herpesvirus 4, Human; D015654:Herpesvirus 6, Human / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007963:Leukocytes, Mononuclear / Q000821:virology; D008213:Lymphocyte Activation; D016133:Polymerase Chain Reaction; D016662:Virus Integration; D017735:Virus Latency
D004279:DNA, Viral