ENUMERATION OF T-CELLS, B-CELLS AND MONOCYTES IN THE PERIPHERAL-BLOOD OF NORMAL AND LYMPHOCYTOTIC CATTLE

  • 1 January 1979
    • journal article
    • research article
    • Vol. 35  (2) , 306-316
Abstract
The rosette-forming capacity of bovine peripheral blood lymphocytes (PBL) was determined with dextran and 2-aminoethylisothiouronium bromide (AET)-treated sheep erythrocytes (SRBC). Dextran and AET enhanced rosette formation; AET-treated SRBC detected a larger percentage of rosette-forming cells and was used in this study. The specificity of rosette formation by bovine thymus-derived (T) lymphocytes was shown by demonstration of rosettes and surface-membrane immunoglobulins (sIg) on different cells in PBL and nylon-wool fractionated lymphocyte populations and rosette formation by a large percentage (83-90%) of thymocytes from 3 bovine fetuses and two 14 mo. old heifers. A procedure was 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 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 20 normal cattle contained approximately 63% T and 11% B (sIg+ latex non-ingesting) lymphocytes. In peripheral blood of 3 cattle with persistent lymphocytosis, a prodromal stage of bovine leukemia, the percentage of B cells was elevated approximately to 59%, whereas T lymphocytes decreased to 35%, providing additional evidence that persistent lymphocytosis is a B cell disease.