A new small RNA virus persistently infecting an established cell line of Galleria mellonella, induced by a heterologous infection.

A persistent infection in a Galleria mellonella cell line was revealed when infected with a maize stem borer picorna-like virus isolated on Sesamia cretica (MSBV). The new virus, completely different from the MSBV, is designated as G. mellonella cell line virus (GmclV), induces spectacular cytopathic effects, and is also considered efficient in vivo. The GmclV is a 29-nm-diameter isometric virus, with single-strand RNA of 2.9 x 10(6) Da molecular weight with a poly(A) tract. Its capsid is constituted of only two major polypeptides, of 34,500 and 32,500 Da, and no minor bands could be detected. The characteristics of the GmclV do not permit us to classify it with assurance. Even though it has not yet been identified as a picornavirus, it can be classified in the small RNA virus group of the Picornaviridae. G. mellonella represents a very interesting model, owing to the fact that two different persistent viruses belonging to the same family were isolated in vivo and in vitro, to further the understanding of the general phenomenon of persistency and induction.