FLOW CYTOMETRIC ANALYSIS OF OVINE PERIPHERAL-BLOOD LYMPHOCYTES

Leukocyte suspensions were prepared from the peripheral blood of 12 sh eep three times at two month intervals beginning at 12 months of age. Monoclonal antibodies and flow cytometric analysis were used to charac terize the cells. There were no significant differences over time ther efore the data from the three time intervals were pooled. The mean per centages and ranges (minimum to maximum) of the major lymphocyte subty pes were: B-cells (29.6%, 11-50), gamma delta T-cells (36.6%, 22-68), CD4(+) T-cells (14.1%, 8-22) and CD8(+) T-cells (12.0%, 4-22). Lymphoc yte subtype percentages appeared less variable within than between ind ividuals. Two populations of B-cells were noted; one population had mo re cytoplasm and light scatter characteristics similar to monocytes wh ile a second population of B-cells was more typical of small lymphocyt es. The nature of the large B-cells requires further study.