Lymphoid cell composition of human tonsils and adenoids as determined by FACS analysis. Tonsillar (□) and adenoid (▪) mononuclear cells or tonsillar IELs (▨) were incubated for 30 minutes with FITC-labeled mAbs anti-CD3, anti-CD19, anti-CD14, or anti-HLA-DR for the detection of T cells, B cells, macrophages, and MHC class II molecules. Cells were then washed, fixed with 1% paraformaldehyde, and stored at 4°C until analyzed by flow cytometry. The results are expressed as the mean percentage ± SD of 5 to 12 separate experiments. *P < 0.05.