Figure 5.

Clonal expansion of CD3- and CD2-activated CD45RA⁺ PBTs, CD45RO⁺ PBTs, and LPTs. After 4 days’ stimulation, CD3 activation induces a greater clonal expansion in both CD45RA⁺ and CD45RO⁺ PBTs than in LPTs, whereas in CD2-activated cells clonal expansion is strikingly greater in LPTs than in both CD45RA⁺ and CD45RO⁺ PBTs. The first peak to the right represents the undivided cell population. The numbers indicate the percentage of divided cells distributed in the subsequent peaks. Freshly isolated CD45RA⁺ and CD45RO⁺ PBTs and LPTs were incubated with 5 μM CFDA and cultured in the absence and presence of CD3 or CD2 mAb for 4 days, and cell divisions were determined by flow cytometry. The figure is representative of six to nine different experiments.