Infection of human cells with murine amphotropic replication-competent retroviruses.
Replication of the murine wild-type 4070A amphotropic retrovirus and a recombinant amphotropic replication-competent retrovirus arising from the PA12 packaging cell line varied considerably among the primate cell types tested. Medium from infected primate fibroblasts and endothelial cells contained the highest viral titers [10(4)-10(5) focus-forming units (ffu)/ml], while most hematopoietic cell lines, such as K562 and MOLT4, were associated with viral titers in the range of 10(3)-10(4) ffu/ml. Interestingly, HTLV-1-transformed T cell lines (TJF-2 and HM) and primary tumor infiltrating lymphocytes (TIL) had very low viral titer (0-10(1) ffu/ml). The low production of virus was not due to low infectivity and, in contrast to the virus, retroviral vectors were expressed without difficulty. Because screening for replication-competent retrovirus (RCR) is an important component of human retroviral-mediated gene therapy clinical protocols, a variety of assays were tested for their ability to detect RCR in virus-exposed cell lines. A biologic assay (3T3 amplification) and polymerase chain reaction (PCR) for the 4070A viral envelope are effective screening methods for RCR, even in cell lines associated with low virus production.
Cornetta
K
K
Molecular Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892.
Nguyen
N
N
Morgan
R A
RA
Muenchau
D D
DD
Hartley
J W
JW
Blaese
R M
RM
Anderson
W F
WF
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers; D005822:Genetic Vectors; D000882:Haplorhini; D006801:Humans; D016246:Lymphocytes, Tumor-Infiltrating / Q000382:microbiology; D051379:Mice; D008969:Molecular Sequence Data; D012190:Retroviridae / Q000472:pathogenicity* / Q000502:physiology; D013601:T-Lymphocytes / Q000382:microbiology; D014779:Virus Replication
D017931:DNA Primers