Fundamental Study on the Induction and Prevention of Preleukemia Condition by Bovine Leukemia Virus

点击翻译按钮获取中文摘要

Persistent lymphocytosis (PL) was experimentally prepared as a pre-leukemia condition and its pathological feature was studied from the viewpoint of virology, immunopathology and morphology.Experiment : As a donor, a cattle aged 2 years was used which responded positively to BLV antibody and had PL with 13, 300 lymphocytes/mul. Three calves aged 7-8 months (A, B and C) were intravenously inoculated with lymphocytes of 10^<10.3>, 10^9, 10^<9.6> respectively (second generation). Then, 10^<9.1>, 10^<9.1>, 10^<8.8> lymphocytes taken from the cattle "A"(positive to BLV antibody, 14, 868 lymphocytes/nul) were intravenously inoculated to each of another 3 cattle(a, b and c)(third generation). The experiment has been still being continues by using 2 animals inoculated with lymphocytes from the animal "a" (forth generation). These animals were investigated from the viewpoints of hematology, virology, immunology and histopathology.Results : (1) PL was induced in 2 animals of the second generation (A and B), 3 animals of the third generation (a, b and c), and 2 animals of the fourth generation 5-8 months after inoculation respectively. (2) With periphocytes, at weeks 1-2 after inoculation reversion of the ratio of T lyphocytes to B lymphocytes was recognized in all of the animals. The number of T lymphocytes (CD4, CD8) was decreased, while that of IgG positive B lymphocytes was increased. (3) Electron microscopy showed numerous virus particles in the peripheral lympocytes of the animals with PL which had been incubated for 24hrs. BLV antigens were detected in the cytoplasm when investigated by fluorescence antibody method using antiserum against BLV. (4) It was found that follicles of lymph nodes became larger in the 3 animals with PL (A, B and a) which were sacrificed at 6-9 months and that the constituent cells hd atypia. These cells sometimes responded positively to anti-tumor associated serum (CEBL-2)