Flow cytometry studies on blood lymphocytes in BLV-infected cattle

Lymphocytes of haematologically and serologically EBB-positive cows were isolated and incubated with CD4, CD8, Cdllc and alpha bovine IgM markers, produced by Int. ILRAD Peter Maesseus. The cells were analysed immediately following fluorescein marking, in flow cytometer (FACS Calibur - Becton Dickinson). The number of proliferating B lymphocytes with increased IgM marker expression was high, testifying to early infection of the cattle with bovine leukemia virus (BLV). The expression of CD4 and CD8 markers in Th and Tc lymphocytes in leukemic cows was more pronounced than in healthy animals. The changes were accompanied by a decreased production of natural killer (NK) cells.