Lymphocyte subset analysis
All the healthy volunteers were taking part in the Public Welfare Scientific Research Project of China (grant no. 201402012)18. The BD Multi-test IMK Kit (cat. 340503) was used to analyze lymphocyte subsets (B cells, CD3 T cells, CD4 T cells, CD8 T cells, and CD32CD56/CD16 natural killer cells). The following mAbs were used to detect T cell subsets: anti-human CD3 (PerCP-Cy5.5), anti-CD4 (FITC; fluorescein isothiocyanate), anti-CD8 (BV510), anti-CD27 (APC; allophycocyanin), anti-CD45RA (PE-Cy7), anti-TCR (PE; phycoerythrin), and anti-TCRgd (BV421) (all from BD Biosciences). Subsets were analyzed as described previously.