Lymphocyte subpopulations in sheep with lymphosarcoma resulting from experimental infection with bovine leukaemia virus.
Sheep were experimentally infected with bovine leukaemia virus (BLV) and developed leukaemia and lymphosarcoma 30-88 weeks later. Ten sheep with lymphosarcoma were necropsied and lymphocyte subpopulations were evaluated in peripheral blood lymphocytes (PBL) and lymphocyte suspensions prepared from a range of lymph nodes, tumours and spleen. The leukaemic phase of BLV infection was characterized by an increase in the number of circulating B lymphocytes. The number of T lymphocytes was also increased with the CD8+ subpopulation proliferating at a much greater rate than the CD4+ subpopulation. In PBL the CD4:CD8 ratio fell rapidly as leukaemia developed, being 1.15 (+/- 0.18) 5-8 weeks before necropsy and 0.38 (+/- 0.09) at necropsy. During this period the number of B lymphocytes increased from 11.2 (+/- 0.7) to 379.4 (+/- 85.8) x 10(9)/L. CD4:CD8 ratios were also low in all lymph nodes and spleens of leukaemic sheep at necropsy. Most of the cells in solid tumours were B lymphocytes but a small population of T lymphocytes with a low CD4:CD8 ratio was identified.
Dimmock
C K
CK
Animal Research Institute, Queensland Department of Primary Industries, Moorooka, Australia.
Ward
W H
WH
Trueman
K F
KF
D000818:Animals; D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology; D001909:Leukemia Virus, Bovine; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D008228:Lymphoma, Non-Hodgkin / Q000276:immunology*; D012756:Sheep; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation