Duck lymphocytes. VIII. T-lymphoblastoid cell lines from reticuloendotheliosis virus-induced tumours

The T strain of reticuloendotheliosis virus (REV-T) obtained, along with the helper chicken syncytia virus (CSV), from the CSO4 cell line was highly oncogenic and rapidly fatal in ducks. Tumours were mainly seen in spleen, but neoplastic cells were observed microscopically in many organs. In vitro REV transformation of duck lymphocytes failed to yield stable cell lines, so cells from organs (blood, bone marrow, spleen, lymph node, bursa of Fabricius) of infected birds were used to establish cell lines. Some of these cell lines have been cloned. The success rates of establishment and cloning were increased if cells were cultured in a range of media containing different supplements; however, medium containing 5% foetal calf serum (FCS) and 5% duck serum was generally most efficacious for initial establishment, while spent medium from the parental line supplemented with a further 20% FCS gave best results for cloning. Cloned cell lines had the morphology of lymphoblastoid cells, with irregular nuclei and diffuse chromatin. Analysis of mRNA extracted from these cell lines showed that the uncloned lines were strongly expressing the β chain of the T cell antigen receptor (TCR) and weakly expressing immunoglobulin (Ig) polypeptides [λ light chain and μ, υ, υ (ΔFc) and α heavy chains in various proportions], suggesting the presence of T and B cells. The cloned cell lines that could be classified were TCR β+ ve T cells. This is the first report of the establishment, cloning and partial characterization of duck lymphoblastoid cell lines.