Histocompatible miniature boar model: Selection of transformed cell lines of b and t lineages producing retrovirus

Abstract

A lymphoblastoid cell line (B1) was isolated in culture following a brief exposure to 5-azacytidine from peripheral-blood mononuclear cells of a boar previously injected with cells (Shimozuma) producing porcine retrovirus (Tsukuba-1) and suffering a severe non-neoplastic syndrome at autopsy. B1 cell line and 5 of its sublines were propagated for more than 100 generations, retaining doubling times comprised between 16.8 and 27.5 hr and growing readily in agarose or agar (plating efficiency: 5 to 50%). Karyotype analyses showed that 4 sublines were nearly diploid, except for cells of L14, which displayed a monosomy affecting chromosome 18 pair. Two sublines (L35 and L45) were considered as being of T-cell lineage, since MSA, antigen was observed on the surface of approximately 30% of cells. Three sublines (L23, L14 and L52) were considered of B-cell lineage, since membrane immunoglobulins were observed on the cell surface. In addition, sublines L23 and L52 were actively secreting immunoglobulin of mu isotype. Retrovirus particles were evidenced in gradient-purified preparation of 200-fold-concentrated cell culture supernatants of the B1 cell line, L14, L35 and L52 sublines, using both a reverse transcriptase activity assay and electron microscopic observation. These cell lines can be used to select for porcine retrovirus variants with transforming potential for lymphocytes of B and T lineages.

Porcine retrovirus: optimal conditions for its biochemical detection

“…RPJ (about 100 passages) and REB (50 passages) were pig kidney cell lines obtained by Jacqueline Gelfi (INRA, France) and by us, respectively, fiom a healthy animal. L 35 and L 52 were tymphoblastoid cell lines isolated in our laboratory from blood of a young inbred miniature boar which had been inoculated intraperitoneally with Shimozuma cells [9]. Also used for the RT assay were different cells freshly isolated from kidneys, spleen, muscle, skin and bone marrow of healthy pigs.…”

“…Porcine retroviruses have been detected in a cell line derived from swine malignant lymphomas (Shimozuma cells) [15], in blood of a miniature swine that had been exposed to strontium-90 radiation and that had developed haematopoietic disorders [4-] and in porcine cell lines after long-term propagation in vitro [11,16]. Recently, we have found retroviruses in lymphoblastoid cell lines derived from pigs that had been inoculated with retroviruses [9]. Generally, retroviruses are identified by immunological methods using antibodies directed against one of the viral structural proteins, which, in most cases, cross-react with type C viruses of other species I-8, 11, 14-] or detected by biochemical assay of their reverse transcriptase (RT) activity.…”

Membrane markers of the immune cells in swine: an update

“…In these studies, care was taken to include a broad panel of lymphoid cells and specialised cell populations in order to ensure that the mAb were clustered appropriately. Thus, in addition to analyses of peripheral blood mononuclear cells (PBMC) and lymphoid tissues, analyses of representative cell subsets and cell lines, such as B-cell lines, [98,99], alveolar macrophages, TCR-expressing cell lines foetal liver cells, SLA I-transfected mouse fibroblasts and T-cell lines have been carried out [164].…”

Cell-mediated immunity to pseudorabies virus: cytolytic effector cells with characteristics of lymphokine-activated killer cells lyse virus-infected and glycoprotein gB- and gC-transfected L14 cells

“…Studies to examine the significance of CTLs against PRV-infected cells have previously been hampered by difficulties in measuring major histocompatibility complex (MHC)-restricted cytotoxicity in pigs. However, miniature pigs inbred for their MHC (Sachs et at., 1976) have now become available, as well as an immortalized L14 B cell line of haplotype d/d (Kaeffer et aL, 1990). The reported suppression by PRV of cellular MHC class I expression (Mellencamp et al, 1991) may also have hampered the detection of PRV-specific CTLs.…”