Part of the lymphocytes were activated and proliferated, and the
expression of CD26 was upregulated after antigen stimulation
Three days after stimulation by immobilized anti-CD3 mAb, the activation
of HPBLs was determined by the measurement of expression of different
lymphocyte activation markers (CD69, CD25, CD71, and CD26). In
comparison to non-activated control cells, the percentage of
CD26+ HPBLs was significantly increased after
stimulation by 85% (33±8% vs. 61±14% of total HPBLs,p <0.001) (Figure 1A) , while the percentages of
CD69+ and CD71+ cells were 6-fold
and 5-fold compared to control cells (54.29± 20.87% vs.9.07±7.28%, p <0.01; 30.6±14% vs. 5.8±2.46%,p <0.05), respectively, and the percentage of
CD25+ HPBLs was 68% higher than the value in the
control group (17.65±6.58% vs. 10.49±9.41%) (Figure
1B) . These results indicate that a substantial part of the HPBLs was
activated after stimulation with immobilized anti-CD3 mAb.
To determine the proliferated new generations of lymphocytes after
stimulation, the CFSE assay was used. As shown in Figure 1C andD , at day three after stimulation, the stimulated group (hollow
black histogram) showed five additional peaks that represent five
increased generations of HPBLs whereas the PBS control group (shaded red
histogram) showed only one peak remaining in the original position,
indicating that no new generation was generated. These results provide
evidence that the lymphocytes proliferated and increased by up to five
new generations after stimulation compared to the lymphocytes of the PBS
control group that had not proliferated within three days.