Establishment and characterization of a cell line derived from Eptesicus nilssonii.

Bats of the genus Eptesicus have several non-retroviral RNA virus-derived sequences in their genomes, among which an endogenous bornavirus-like L element, named eEBLL-1, was suggested to encode functional proteins in the hosts. However, the function of eEBLL-1 remains unclear due to a lack of appropriate investigation tools, such as cultured cells expressing eEBLL-1. Here, we established a continuous cell line, named HAMOI-EnK cells, from kidney of Eptesicus nilssonii. HAMOI-EnK cells are robust and could be passaged for at least 10 months. eEBLL-1 in the genomes of HAMOI-EnK cells retains an intact open reading frame. Additionally, eEBLL-1 is transcribed in the sense-orientation in cells. To our knowledge, this is the first report to demonstrate that eEBLL-1 is transcribed in cultured cells.