FACS analysis of hCD4 expression.

(A) LN cells. Double staining with antihuman CD4 (hCD4) and antimouse CD4 (mCD4) or mouse CD8 (mCD8) monoclonal antibodies was carried out. The percentage of T cells expressing hCD4 in a representative mouse for each line is shown. Note that the leakiness of the hCD4 expression on the mature CD8⁺ T cells was absent in the CD4F Tg line. (B) Peritoneal macrophages. Double staining of plated peritoneal macrophages was done with anti-hCD4 and anti–Mac-1 antibodies. The percentage of macrophages expressing Mac-1 and hCD4 is shown. The quadrant settings are based on unstained controls. (C) DCs. Triple staining of enriched LN DCs. Cells that were gated for CD11c⁺CD11b/Mac-1⁺ (myeloid) and CD11c⁺CD8α⁺ (lymphoid) expression (i) show expression of hCD4 (ii). The thymic DCs were all CD11c⁺CD8α⁺. The bars in each panel in ii show the staining of hCD4 on DCs from non-Tg control mice.