Induction of perforin expression in CD8 lymphocytes.

<p>Heparinized blood was incubated in RPMI medium in presence or absence of a lysate from FLK-BLV cells. After 5 days of culture, brefeldin A was added during 4 hours, leukocytes were permeabilized and CD8 and perforin expression were quantified by flow cytometry. (A) Representative dot plots of CD8 (x axis) and perforin (y axis) labeling of leukocytes from control, infected and splenectomized infected sheep, with and without antigenic stimulation. (B) Induction of perforin expression calculated as the ratio between the proportion of CD8 expressing perforin with and without antigenic stimulation. These values were measured 4 times (during a 3 months period) in control, BLV-infected and splenectomized BLV-infected sheep. Statistical relevance (N.S. not significant; *** very highly statistically significant p<0.001) was calculated according to the unpaired two-tailed student t test with Welch's correction.