IVIg priming in vivo reduced the cell engagement property of PLTs in vitro. Experimental schemes of in vivo (A) and in vitro (B) IVIg priming of PLTs and splenic LCs and the subsequent PLT-CD14⁺ LC engagement experiment. Quantitative flow cytometric analysis revealed the relative PLT-CD14⁺ LC engagement levels as the PLTs and CD14⁺ LCs were differentially primed with IVIg or vehicle in vivo (columns 1-4) and in vitro (columns 5-8), respectively (C). *P < .05. n = 6 (3 experiments with 2 replicates). Data are mean ± SD.