CD86 and dengue disease: Gating on CD19+CD27− naïve B cells, we observed that activation after TLR stimulation is decreased in dengue patients compared to healthy donors as measured by the lower percentage of early activated, CD69+ naïve B cells or naïve B cells expressing CD86, a co-stimulatory protein for T cell activation during antigen presentation (median CD69+, 5.1% vs. 17.4%; P < 0.05) (median CD86+, 8.3 vs. 26.5%; P < 0.05) (Figures 5A,B).