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.
MCM: Authors state this is the 2nd case report of HHV7
isolated from a CFS pt.
Secchiero P, Berneman ZN, Gallo RC, Lusso P