Characterisation of cell lines transformedin vivoandin vitroby reticuloendotheliosis virus‐t strain

Abstract

A total of 39 cell lines were established from the spleen, liver, bone marrow and thymus of chick embryos and young chickens into which reticuloendotheliosis virus (REV)-T strain was inoculated, which were incubated in vitro. Forty-six sublines were obtained from these cell lines by cloning. For establishment of three in vitro-transformed cell lines, the spleen and bone marrow cells from chickens were exposed to the culture fluids of some cell lines. These established cell lines were designated as RECC-KU 5 to 46. The 88 cell lines thus established were examined for cell surface determinants by immunofluorescence assay. Although 87 of the cell lines reacted with rabbit anti-bursacyte serum (ABS), they showed no reaction with rabbit anti-thymocyte serum (ATS). The remaining cell line reacted with ATS at a high rate (31.7%), and with ABS at a rate of 1.4%. Cell surface immunoglobulin was found, at a low rate, in only two cell lines. Absorption of ABS by the established cell lines caused decrease in the percentage of fluorescence-positive bursacytes. These results suggest that all except one of the established cell lines are of B-cell origin. When culture fluids of 36 cell lines were inoculated into 1- to 2-day-old chickens, lethal reticuloendotheliosis and/or abnormal feathering ('nakanuke') was observed in 33 of them. In vitro infectivity assay revealed that 31 of the 36 cell lines were virus producers.