Handlings with lentiviral transduced cells under non-contained conditions

COGEM has been asked to advice on handlings with mammalian cells infected with a genetically modified (gm) virus (lentiviral vector). It concerns experiments in which a microscope is used. The applicant holds already a license to perform experiments under containment level MLII. However, due to practical reasons it is not possible to perform experiments with a microscope in a containment unit. Therefore, the applicant requests a license to perform these experiments, under non-contained conditions Before the experiment starts, the gm-virus will be tested for its loss of ability to replicate (Replication Competent Retrovirus (RCR)). After proving the non-replicative status of the gm-virus, the mammalian cells will be infected with this virus. Subsequently the cells will be cultured for one week under relatively high physical containment (ML-II). During this period the remaining virus will decrease 50 percent every ten hours. After culturing, the cells will be washed once with human serum. The COGEM advises an additional washing step with medium to further reduce the quantity of gm-virus to non-detectable levels. Noteworthy, the gm-virus has lost its ability to transmit to non-infected cells. Considering the above-mentioned, in COGEM’s opinion, the proposed activities, pose a negligible risk for human health and the environment and therefore can be carried out under non-contained conditions.