Abstract
Establishment of latently infected cell lines from primary effusion lymphomas (PEL) presently is the most efficient system for the propagation of clinical strains of human herpesvirus 8 (HHV-8) in culture. Here we describe a new approach to culture productively replicating HHV-8 from patient samples. A BJAB-derived B-cell line, BBF, was found to retain HHV-8 longer, to support the latent and lytic replication programs, and to produce transmissible virus. Supernatants from n-butyrate-treated peripheral blood mononuclear cells of 24 HHV-8-seropositive renal transplant recipients were used to infect BBF cells, and replicating virus was detected in cultures from 11 patients. Moreover, BBF cells infected with saliva strains showed a highly productive profile regardless of the initial viral load, which confirms that infectious HHV-8 can be present in saliva and also suggests that saliva strains may exhibit a high tropism for B lymphocytes. In conclusion, we established an in vitro system that efficiently detects HHV-8 in samples with low viral loads and that produces infectious progeny. BBF cells can be used to propagate HHV-8 from different biological samples as well as to clarify important issues related to virus-cell interactions in a context distinct from endothelial and PEL-derived cell lines.