List of all cell lines screened for 15 viruses from Screening for 15 pathogenic viruses in human cell lines registered at the JCRB Cell Bank: characterization of <i>in vitro</i> human cells by viral infection

Human cell lines have been used in a variety of research fields as an <i>in vitro</i> model. These cells are all derived from human tissue samples, thus there is a possibility of virus infection. Virus tests are routinely performed in clinical practice, but are limited in cell lines. In this study, we investigated 15 kinds of viruses in 844 human cell lines registered at the Japanese Collection of Research Bioresources (JCRB) Cell Bank. Our real-time PCR analysis revealed that six viruses, EBV, HTLV-1, HBV, B19 V, HHV-6 and HHV-7, were detected in 43 cell lines including five de novo identifications of EBV, B19 V or HHV-7 carriers. Of them, 20 cell lines were transformed by intentional infection <i>in vitro</i> with EBV or by HTLV-1. Viruses in the other 24 cell lines correspond to an <i>in vivo</i> infection. Of them, 17 cell lines were established from patients diagnosed with virus-associated diseases. However, the other seven cell lines originated from <i>in vivo</i> cells unrelated to disease or cellular tropism. Our approach to screen for a set of 15 viruses in each cell line has efficiently worked to identify these rare cases. Virus tests in cell lines contribute not only to safety assessments but also to investigation of <i>in vivo</i> viral infection which can be a characteristic feature of cell lines.