title: Comparison between S+L- assay and LacZ marker rescue assay for detecting replication-competent gammaretroviruses.
abstract: To avoid contamination of adventitious gammaretroviruses in biological products such as vaccines, it is necessary to check the master seed cells for manufacturing. There are several assays to detect infectious gammaretroviruses. Among these, sarcoma-positive, leukemia-negative (S+L-) assay is a classical infectivity assay, which is often recommended in governmental guidelines. The S+L- cells used in S+L- assay generate unique focus upon the infection of replication-competent gammaretroviruses. Although S+L- assay is well recognized for the detection, their applicability is questionable in some cases. On the other hand, LacZ marker rescue (LMR) assay detects infectious gammaretroviruses by transducing LacZ marker gene to the target cells, which shows lacZ-positive foci if the infectious virus is present. In this study, we compared LMR and S+L- assays for detection of a variety of endogenous and exogenous gammaretroviruses. As results, LMR assay could detect all gammaretroviruses examined. On the other hand, S+L- assay using feline S+L- cells, termed QN10S, could not detect porcine endogenous retrovirus (PERV) subgroups A/B. Further, S+L- mink cells could not detect feline leukemia virus subgroups B in addition to PERV-A/B. These data indicate that LMR assay is better suited to detect wider range of gammaretroviruses.
authors.affiliation: Laboratory of Signal Transduction, Department of Cell Biology, Institute for Virus Research, Kyoto University, 53 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Hashimoto-Gotoh
authors.affiliation: Laboratory of Signal Transduction, Department of Cell Biology, Institute for Virus Research, Kyoto University, 53 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Yoshikawa
authors.affiliation: Laboratory of Signal Transduction, Department of Cell Biology, Institute for Virus Research, Kyoto University, 53 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan. Electronic address: takavet@gmail.com.
authors.forename: T
authors.initials: T
authors.lastname: Miyazawa
mesh_terms: D001681:Biological Assay; D017988:Gammaretrovirus / Q000302:isolation & purification* / Q000502:physiology; D005819:Genetic Markers; D057809:HEK293 Cells; D006801:Humans; D007763:Lac Operon; D060888:Real-Time Polymerase Chain Reaction; D014779:Virus Replication
chemical_list: D005819:Genetic Markers
keywords: Endogenous retrovirus; LacZ marker rescue assay; S+L− assay