Figure 3.

PBMC proliferative response to recombinant proteins VIR and MSP1₁₉ from individuals recently exposed to P. vivax malaria. PBMC proliferation assay was performed as described in the Methods section. Each recombinant protein VIR, MSP1₁₉ or GST was tested in final concentration of 2 and 10 μg/ml. Individuals were considered as positive responders when they showed SI > 2.5 for at least one of the two concentrations of recombinant protein when compared to PBMC cultures containing the GST protein alone (VIR proteins) or medium alone (MSP1₁₉). Symbols represent the SI obtained after stimulation with each antigen at the final concentration of 2 μg/ml (A) or 10 μg/ml (B). The horizontal lines represent the SI = 2.5. Individuals never exposed to malaria did not respond to antigen stimulation (data not shown). PBMC were also stimulated with Con A as positive controls. The SI obtained after stimulation with this mitogen varied from 15 to 178.2 (data not shown).