Propagation and characterization of human herpesvirus-7 (HHV-7) isolates in a continuous T-lymphoblastoid cell line (SupT1).
After initial culture of HHV-7 in PHA-stimulated human cord blood mononuclear cells (HCBMC), six HHV-7 isolates were propagated successfully in an immature continuous T-lymphoblastoid cell line SupT1. All six isolates infected efficiently the SupT1 cells, and the infected cells became grossly enlarged and multinucleated 7-21 days post-infection. Various stages of HHV-7 morphogenesis were detected. Cell-free supernatants from HHV-7-infected SupT1 cells were infectious to HCBMC as well as to SupT1 cells. The HHV-7-infected SupT1 and HCBMC cell lysates contained more infectious virus than the centrifuged cell culture fluid supernates from the same culture. The HHV-7 isolates H7-2, H7-3, JHC, and JB, concentrated 500 times, had average infectivity titers of 10(3.0) TCID50/ml while strains H7-4 and KHR titered approximately 1-2 logs higher. When all six HHV-7 isolates were propagated in SupT1 and culture fluid supernatants were examined 14-21 days post-infection by negative stain electron microscopy they contained an average of 1.9 x 10(9) virus particles/liter. IFA and ELISA, using HHV-7/SupT1 cell lysate as an antigen, seem to correlate well in detecting high and low HHV-7 antibody in sera from chronic fatigue patients and healthy donors as controls. HHV-7 from SupT1 cell culture was free of HHV-6 and other human herpesviruses as tested by PCR, and the HHV-7 PCR signal was still strong when the viral preparation was diluted to 4.82 x 10(2) genome copies. Since HCBMC are expensive to obtain and available in only small amounts, it is difficult to obtain large quantities of HHV-7 antigen. On the other hand, the SupT1 cell is an excellent source to produce consistently sufficient quantities of HHV-7 for purification studies, development of immunodiagnostics, in vivo infectivity studies, evaluation of antiviral drugs, and molecular biological studies.
Advanced Biotechnologies Incorporated, Columbia, MD, USA.
D V
DV
Ablashi
M
M
Handy
J
J
Bernbaum
L G
LG
Chatlynne
W
W
Lapps
B
B
Kramarsky
Z N
ZN
Berneman
A L
AL
Komaroff
J E
JE
Whitman
D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral; D002460:Cell Line; D002648:Child; D003588:Cytopathogenic Effect, Viral; D004279:DNA, Viral / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D015673:Fatigue Syndrome, Chronic / Q000821:virology; D005455:Fluorescent Antibody Technique; D016199:Herpesvirus 7, Human / Q000254:growth & development* / Q000302:isolation & purification*; D006801:Humans; D008213:Lymphocyte Activation; D008854:Microscopy, Electron; D009024:Morphogenesis; D016133:Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D013601:T-Lymphocytes; D014776:Virus Cultivation / Q000379:methods
D000914:Antibodies, Viral; D000956:Antigens, Viral; D004279:DNA, Viral