Biological and molecular characteristics of human herpesvirus 7: in vitro growth optimization and development of a syncytia inhibition test.
Two isolates of human herpesvirus 7 (HHV-7) were recovered from phytohemagglutinin-activated peripheral blood mononuclear cells of a patient with chronic fatigue syndrome and of a healthy blood donor. A genetic polymorphism between the two isolates was detected by Southern blot analysis using a novel HHV-7 genomic clone (pVL8) as a probe. We developed optimized conditions for the in vitro propagation of HHV-7 by using enriched populations of activated CD4+ T lymphocytes derived from normal peripheral blood, resulting in the production of high-titered extracellular virus (> 10(6) cell culture infectious doses/ml). Bona fide syncytia formation was documented both in normal CD4+ T lymphocytes and in the Sup-T1 CD4+ T-cell line following infection with high-titered HHV-7. To identify neutralizing antibodies to HHV-7, a syncytia-inhibition test was developed. Variable titers of syncytia-neutralizing antibodies were detected in all the human sera tested, thus confirming the high prevalence of HHV-7 in the human population.
Secchiero
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Laboratory of Tumor Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
Berneman
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ZN
Gallo
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RC
Lusso
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P
D000914:Antibodies, Viral / Q000032:analysis / Q000276:immunology; D001483:Base Sequence; D015139:Blotting, Southern; D004279:DNA, Viral; D015673:Fatigue Syndrome, Chronic / Q000382:microbiology; D015726:Giant Cells / Q000382:microbiology*; D006566:Herpesviridae Infections / Q000276:immunology / Q000382:microbiology; D016199:Herpesvirus 7, Human / Q000254:growth & development* / Q000276:immunology / Q000648:ultrastructure; D006801:Humans; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D011110:Polymorphism, Genetic
D000914:Antibodies, Viral; D004279:DNA, Viral