title: Enumeration of T cells, B cells and monocytes in the peripheral blood of normal and lymphocytotic cattle.
abstract: The rosette-forming capacity of bovine peripheral blood lymphocytes (PBL) was determined with dextran and 2-aminoethylisothiouronium bromide (AET)-treated sheep erythrocytes (SRBC). Both dextran and AET-enhanced rosette formation; however, AET-treated SRBC detected a larger percentage of rosette-forming cells and thus was used in this study. The specificity of rosette formation by bovine thymus-derived (T) lymphocytes was shown by (1) demonstration of rosettes and surface-membrane immunoglobulins sIg) on different cells in PBL and nylon-wool fractionated lymphocyte populations and (2) rosette formation by a large percentage (83--90%) of thymocytes from three bovine foetuses and two 14-month-old heifers. A procedure was also developed to identify bovine monocytes by latex phagocytosis and 10--30% latex-ingesting cells were detected in PBL preparations isolated by Ficoll-Hypaque flotation. The frequency of sIg-bearing latex-ingesting, and sIg-bearing latex non-ingesting cells in bovine peripheral blood was also determined. These procedures were utilized to determine the distribution of T and bone-marrow derived (B) lymphocytes in peripheral blood of normal and lymphocytotic cattle. PBL from twenty normal cattle contained approximately 63% T and 11% B (sIg+ latex non-ingesting) lymphocytes. In peripheral blood of three cattle with persistent lymphocytosis, a prodromal stage of bovine leukaemia, the percentage of B cells was elevated approximately to 59% whereas T lymphocytes decreased to 35%, thus providing additional evidence that persistent lymphocytosis is a B-cell disease.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology*; D005260:Female; D007958:Leukocyte Count; D008218:Lymphocytosis / Q000276:immunology / Q000662:veterinary*; D009000:Monocytes / Q000276:immunology; D011947:Receptors, Antigen, B-Cell / Q000032:analysis; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D011947:Receptors, Antigen, B-Cell