Detection of Bovine Leukemia Virus in B-Lymphocytes by the Syncytia Induction Assay 2

Abstract

Bovine peripheral blood lymphocytes (PBL's) from 3 cows and 1 steer infected with bovine leukemia virus (BLV) were separated by fractionation through nylon wool columns into nylon-adherent and nonadherent cell populations. Nylon-adherent cells were enriched in B-lymphocytes, as determined by the presence of surface membrane immunoglobulins (slg), whereas nylon-nonadherent cells or "non-B-lymphocytes" contained few slg-bearing cells. PBL's and separated B- and non-B-lymphocyte populations were assayed for the presence of BLV by the induction of syncytia in bovine embryonic spleen cells. PBL's and B-lymphocyte populations both produced many syncytia, whereas non-B-lymphocytes yielded few or no syncytia. The specificity of syncytia formation by anti-BLV serum. PBL's from 2 control animals were negative for syncytia induction. This study presents further evidence that B-lymphocytes are the target cells for BLV infection.

T cell proliferative response to bovine leukaemia virus (BLV): identification of T cell epitopes on the major core protein (p24) in BLV-infected cattle with normal haematological values

“…In some cases, animals can develop persistent lymphocytosis (PL) and/or lymphoid tumours (for reviews see : Burny et al, 1987;Van der Maaten & Miller, 1990). This B lymphocytotropic (Paul et al, 1977;Levy et al, 1987), trans-activating (Rosen et al, 1986;Derse, 1987Derse, , 1988 retrovirus induces an antibody response mainly against its two major fftructural proteins: the external membrane glycoprotein gp51 and the major core protein p24 (Miller & Van der Maaten, 1976;Bex et al,, 1979;Meirom et al, 1985). These antibodies may persist throughout the animals' life and even increase as the disease progresses toward PL and/or tumours.…”

Establishment and Propagation of a Bovine Leukaemia Virus-producing Cell Line Derived from the Leukocytes of a Leukaemic Cow

“…In view of the fact that in cattle natural BLV infection is restricted to lymphocytes (Paul et al, 1977;Kenyon & Piper, 1977;Kettmann et aL, 1978), we have investigated the possibility of obtaining in vitro established cell lines of lymphoid origin from cattle with lymphosarcoma which spontaneously release BLV or from normal cattle.…”

Monographs on the Evaluation of Carcinogenic Risks to Humans

“…BL V virions are difficult to identify in neop1astic tissue, but can be found in normal or neop1astic lymphoid cells from BL V -infected catt1e or sheep (Jensen et aL., 1991;Powers & Radke, 1992). Apart from the difference in host range, a notable difference between BL V and HTL V is that infection by BL V is associated with malignancy of B cells, whereas HTL V affects T cells (Paul et al, 1977).…”

“…Lymphoid leukaemia and localized lymphosarcoma frequently occur together (Gatei et al, 1989;Murakami et al, 1994a). (Paul et al, 1977) and the proportion of Blymphocytes in the peripheral b100d of BL V -positive animaIs increases before any potential increase in the number of circulating lymphocytes (Fossum et al,i 988).…”