Influence of adjuvant on MSP4 or MSP5-induced splenocyte proliferation. Splenocytes from mice immunized with MSP4 or MSP5 in different adjuvants were isolated, stained with CFSE and cultured in the presence of MSP4 or MSP5 at 10 μg/ml. HBsAg was used as an unrelated antigen control. PHA and medium alone were used as positive and negative controls respectively (data not show). After 5 days, proliferation was detected by the presence of cells with a decreased fluorescence intensity compared with the negative control (medium control). The frequencies of MSP4 (Panel A) or MSP5 (Panel B) specific proliferating cells are expressed as percentages of the total population. Proliferating populations were identified and quantified by gating specific proliferating cells previously stained with anti-CD4, CD8 or CD19 PE labeled monoclonal antibodies. The distribution of proliferating populations is showed as percentages of the total number of MSP4 (Panel C) or MSP5 (Panel D) stimulated proliferating cells.